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2020-10-22 MP COC Item 7a Attachment 1 Eng Max Field-Master Plan Document_1
MAX FIELD/RIENSTRA PARK Accessibility Study MAX FIELD / RIENSTRA PARK Accessibility Study September 24, 2020 TABLE OF CONTENTS Project Introduction 3 Problem Statement 4 Site Analysis Land ownership 5 Existing Conditions 6 Site biology 7 Geotechnical Investigation 8 Process 9 Plan Recommendations Site Master Plan 10 Zone 1 11 Zone 2 14 Zone 3 16 Zone 4 17 Zone 5 18 Zone 6 19 Appendix 20 A - Full Size Plan B - Cost Estimate C - Geotechnical Report D - Biological Memo MAX FIELD / RIENSTRA PARK Accessibility Study September 24, 2020 MAX FIELD / RIENSTRA PARK Accessibility Study September 24, 2020 3 PROJECT INTRODUCTION Provide ADA Compliance Upgrades to Park Elements at and around Ball Fields • Walkways, ramps and stairs • Dugouts • Bleachers • Seating areas • Parking areas Improve Access to Adjacent Areas • Restored connection to Loma Verde Recreation Center & Loma Verde Elementary School • Connection to potential SDG&E overflow parking lot Accommodate Current and Future Parking Needs • Increased parking opportunities • Overflow parking options, including recreation center parking lot Local map Background Max Field / Rienstra Park is a neighborhood park located in an established neighborhood located at 1500 Max Avenue within the City of Chula Vista. The 13.26 acre park spans two parcels and consists of 7 baseball fields of varying dimensions for a range of age levels of organized sports play. The park is home to numerous sports leagues including South Bay Little League, PONY baseball and softball and a Challenger division providing team participation for disabled youth. The site also has bleachers, restroom facilities, a 107-stall parking lot and two concession stands. The concession stands are not city owned facilities; they are owned and operated by each of the two youth baseball leagues operating on site between February/March and July of each year. The park is adjacent to the Loma Verde Recreation Center and was previously linked by a wooden staircase and pedestrian bridge, which were originally installed in the 1980's and provided park users with easy access to the recreation center parking lot over the Palm Road Drainage Channel. The staircase and pedestrian bridge fell into disrepair and were removed in the summer of 2018 at the end of its lifespan, when it was identified as a potential risk for public safety. This study addresses park accessibility concerns, upgrades to deteriorating park components, parking needs and restoration of the connection to the Loma Verde Recreation Center across an existing drainage channel. The baseball fields' high use cannot be fully accommodated with the park's existing parking lot; overflow parking options are required to meet demand. The City of Chula Vista funded this study through Measure P a temporary ten-year tax to fund high priority infrastructure needs. This report summarizes the suggested improvements in accordance with the project goals and objectives listed below. Goals & Objectives N 3/27/2020 Chula Vista - Google Maps https://www.google.com/maps/place/Chula+Vista,+CA/@32.6316887,-117.164615,11z/data=!3m1!4b1!4m5!3m4!1s0x80d94e4565c3aacf:0x46ccb8734b8f2bd3!8m2!3d32.6400541!4d-117.0841955?hl=en 1/3 Map data ©2020 INEGI 2 mi Chula Vista ê Regional mapN Identify and Improve Drainage Issues • Palm Road Drainage Channel • Bioretention planting areas Conform to Chula Vista Landscape Manual • Improvements to parking lot and stall sizes • Improvements to landscape with trees and planting Upgrade, Repair and Improve Access to Existing Structures • Concessions buildings • Restrooms • Retaining Walls Identify Additional Improvement Opportunities • Future improvements outside of the current project scope E. ORANGE AVE MAX AVE MAX FIELD / RIENSTRA PARK Accessibility Study September 24, 2020 4 B. Walkways have steps without equal accessible sloped or ramped option D. Cage posts in dining area block circulation routes, and site furnishings do not meet clear floor area requirements A. Some routes around fields are not developed or accessible F. Retaining walls are cracked and deteriorating C. Dugout entry and exit are not accessible and require crossing a step E. Drainage infrastructure is aging and is not protected from adjacent walkways; sloped paving areas exceed maximum slope requirements PROBLEM STATEMENT Existing Site Issues Parking Capacity and Layout • The existing parking lot does not accommodate the quantity of visitors during events or peak use. Use of adjacent land parcels for overflow parking will require coordination with other land owners. (see Parcel Map on page 5 for land ownership) • Overflow parking was previously accommodated at Loma Verde Recreation Center. Restoration of a pedestrian connection to the recreation center will enable use of its parking lot and reduce the park’s impact to the surrounding neighborhood. • The existing parking lot stall sizes and layout do not meet current Chula Vista Municipal Code size requirements. Improvements to the parking lot will need to correct the stall sizes as well as address non-compliant slopes at ADA parking stalls, which are currently too steep. Non-Accessible Connections and Amenities • Pedestrian connections around ball fields and to surrounding streets are incomplete or not fully accessible. (see image A) • Circulation routes include steps or stairways without equal ADA access ramps. (see image B) • Pedestrian connections to vehicular areas such as parking lots lack required detectable warnings for people with vision impairments. • Existing pedestrian paths exceed maximum slope requirements. • Dugouts lack required ADA clearances and have stepped entries that prevent a flush accessible entry. (see image C) • Seating areas do not have required circulation clearances or accessible seating options. (see image D) • Bleacher locations prevent required ADA circulation clearances. • Restoration of connection across Palm Road Drainage Channel is required to access Loma Verde Recreation Center and its parking lot. Site Infrastructure • Existing v-ditch and other drainage infrastructure is failing, leading to downhill erosion. (see image E) • Retaining walls are deteriorating and failing. (see image F) Vegetation and Soils • Some steep slope areas lack vegetation and are subject to erosion. • Development of vegetated areas of the site will require mitigation per Biological Resources Study. (See Site Biology on page 7 for locations) • Adjustments to the Palm Road Drainage Channel will require extensive permitting. A range of existing conditions inform and guide the proposed improvements to the park. In order to meet the accessibility and compliance goals of the master plan, issues related to site context and existing infrastructure are explored and addressed. These issues include but are not limited to: MAX FIELD / RIENSTRA PARK Accessibility Study September 24, 2020 5 SITE ANALYSIS SDG&E owned land Parcel map showing contextual land ownership SDG&E SDG&E E. ORANGE AVE LARKHAVEN DRMAX AVE N Land Ownership The land to the north and northeast of the park entrance are under SDG&E ownership. This master plan discusses the option for a potential overflow parking lot on the SDG&E land. Any improvements to these parcels will require additional permission and coordination with SDG&E. A utility enclosure maintained by SDG&E and a pump station maintained by the City of Chula Vista are both within the park property. For purposes of this study it was assumed that these existing utilities should remain in place and provide constraints on emergency access. Relocation or changes to these utilities could provide an overall benefit to the project but require coordination with SDG&E and the City of Chula Vista. LOMA VERDE RECREATION CENTER & ELEMENTARY SCHOOL Existing SDG&E utility enclosure Existing Max Field Sewage Pump Station SDG&E utility enclosure City of Chula Vista CV pump station MAX FIELD / RIENSTRA PARK Accessibility Study September 24, 2020 6 SITE ANALYSIS E. ORANGE A V E MAX AVELARKHAVEN DRSDG&E Park Rienstra Park Site analysis diagramN Existing Conditions The existing park is situated between Max Avenue to the east and E. Orange Avenue to the south. While its context near residential communities and the Loma Verde Recreation Center are opportunities for the park, its physical conditions and layout need to be accounted for in planning for park accessibility and use. SITE OPPORTUNITIES Proximity • The park is nestled in a valley between an established residential communities, and within close proximity to Loma Verde Recreation Center & Elementary School. • The park is within close proximity to open space to the north. Views • Steep slopes on both sides of the park allow views into it from the adjacent homes, school and community center. SITE CONSTRAINTS Vehicle Parking and Circulation • The current parking lot layout is inefficient and does not conform to the City of Chula Vista Municipal Code. Stall size and layout do not meet parking standards, and ADA parking stalls exceed maximum grade requirements. • Existing parking contains inadequate standard and van accessible parking stalls. Pedestrian Circulation • Steps, staircases and steep slopes to accommodate changes in grade create inaccessible routes. • The current locations of the bleachers for each field sit within the walkways and in some places prevent appropriate circulation clearances. • Field dugouts contain one step down creating a trip hazard as well as preventing universal access. • Overhead posts from the field backboards are obstructions resulting in non-compliant seating areas. Access to Surrounding Context • The park lacks any physical connection to the Loma Verde Recreation Center and Loma Verde Elementary School. A former wooden stairway previously connected the park with the Loma Verde Recreation Center, but it was removed after it fell into disrepair at the end of its life cycle. • Bus stops are nearby on E. Orange Avenue at Loma Lane, however the E. Orange Avenue park entrance is now closed. Park visitors must enter the park through a gated entry on Max Avenue. Steep Slopes • Moderate erosion has taken place on the site due to the removal of existing trees and lack of a protective vegetation layer. • The growth of permanent vegetation has not been successful partially due to lack of appropriate irrigation. • The site geology of sandstone and sand contributes to its erosive nature. • The existing V-ditch was constructed with the original fields in the 1960s. It has deteriorated and cracked; runoff has both overtopped or run below it, which adds to slope erosion (see red V-ditch on Biological Resources Map). Park Steep Slopes Non-compliant Parking Non-compliant Hardscape Structures Views Former Bridge Failing Retaining Walls Former Access Gate Pedestrian Circulation Informal Pathways Drainage Legend LOMA VERDE RECREATION CENTER & ELEMENTARY SCHOOL LOMA LN MAX FIELD / RIENSTRA PARK Accessibility Study September 24, 2020 7 SITE ANALYSIS Biological Resources Map Site Biology The existing site is largely comprised of developed land and associated non-native landscapes. Confining redevelopment to the existing developed areas, such as the ball fields, parking lot and facilities, will limit impacts to biological resources. Any changes to the undeveloped areas, such as the vegetated slopes or stream channel, will require additional coordination, review, permitting and mitigation. These requirements are listed below and further described in the Biological Review memorandum in Appendix C. Vegetation • A site visit was conducted in July 2019 to evaluate general vegetation communities and the potential to support special-status wildlife plant species. General vegetation mapping with general locations and habitat types is shown at right; focused surveys for rare plants or sensitive wildlife species were not conducted. Sparse, non-native vegetation zones are found along the park’s steeply sloped sides. • Some pockets of disturbed habitat can be found within non-native grassland. • Impacts to non-native grassland require mitigation ranging from 0.1:1 to 1:1 per the Chula Vista Subarea Plan. • Impacts to maritime succulent scrub require mitigation ranging from 1:1 to 2:1 per the Chula Vista Subarea Plan. • A biologist should review the path location between the Loma Verde Recreation Center / Loma Verde Elementary School and the park to determine that it is located within the least sensitive portion of the project site. Palm Road Drainage Channel • Boundaries of existing channel were mapped with a GPS unit in July 2019, although a formal jurisdictional delineation for the site was not conducted. The existing channel and wetland delineation flow north to south and follow the western portion of the park, as shown in blue at right. • The Biological Review recommends locating all development outside of the Palm Road Drainage Channel. Any impacts to the drainage channel will require permits from the following regulatory agencies: U.S. Army Corps of Engineers (USACE), Regional Water Quality Control Board (RWQCB) and the California Department of Fish and Wildlife (CDFW). • Bridging the channel would not require permits listed above or associated mitigation, as long as all abutments are outside of the channel limits. N Project Boundary Channel Limits 26 x 5’ Culvert Vegetation V-Ditch Legend Developed Maritime Succulent Scrub Non-Native Grassland Non-Native Woodland Sparsely vegetated slopes Drainage channel along park’s western edge E MAX FIELD / RIENSTRA PARK Accessibility Study September 24, 2020 8 SITE ANALYSIS Geotechnical Investigation A geotechnical investigation was completed in June 2020 to study slope erosion issues and the retaining wall damage for the slope and retaining wall extending to the west and southwest from Max Avenue. It addressed both engineering geologic and geotechnical conditions through literature review, field exploration, laboratory testing, conclusions and recommendations. Observations and recommendations are list below, with additional and complete recommendations described in the full Geotechnical Report in Appendix D. Slope Stabilization and Remediation • The slope’s loose colluvial soil can move down slope due to gravity and surface runoff, especially in areas where there is no vegetation. The bedrock units are fairly young, are not well cemented and are made of up mainly sand. Over time the bedrock units have eroded and that subsequent soil has moved downslope through natural processes. Temporary stabilization methods are recommended in the areas where erosion has occurred, in addition to minor work to lower any areas over steepened from erosion. • The slope appears stable and is 3:1 (horizontal to vertical) at it’s steepest and 5:1 at the retaining wall. There are no indications of deep slope failure; areas where vegetation has not regrown reflect typical surface instability. • Vegetation on the slope is not supported by a permanent irrigation system. Vegetation has not regrown in areas of surface erosion. The addition of an irrigation system and hydroseeding the slope are recommended to protect the slope from surface erosion. • Ground squirrel burrows on the slope accelerate erosion of the slope face. A program should be implemented to limit the burrows on the slope. • A concrete v-ditch on the slope is in poor condition. Runoff that overtops the v-ditch or runs under it erodes the downslope side of the v-ditch and sometimes allows water to run underneath it. It is recommended to reconstruct the v-ditch and to install a new drainage system to current standards. A maintenance program should also be incorporated to clean the v-ditch of soil, to fill cracks in the v-ditch and to repair areas of erosion around the v-ditch. • Additional recommendations to reduce surface water runoff and address loose soils are included in the Geotechnical Report. Retaining Wall • The 55-60 year old masonry retaining wall at the base of the slope ranges from 2 feet to about 7-8 feet in height. It is in poor condition and appears to have had modifications in the past and have several cracks and areas that are bulging outward. The retaining wall has deteriorated likely due to elevated salt levels in the air, a lack of a drain behind the wall, previous modifications to the wall and the pressure being exerted on the wall by the vegetated slope. • The Geotechnical Report recommends removal and reconstruction of the retaining wall using current standards and materials. It also recommends removal of vegetation within 5 feet of the top of the wall to reduce pressure at the backside of the new wall, removal of loose soil behind the top of wall and construction of a v-ditch at the top of the wall to divert runoff to drainage inlets. Max Field at Rienstra Park Retaining Wall and Slope Erosion City of Chula Vista RMA Job No.: 20-0287-01 Figure 1 SITE LOCATION MAP Base Map: Google Earth SITE Area with little or no vegetation Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Figure 3 Photograph 5. V-ditch with grass growing cracks and joints in concrete. Grass growing on downslope side of v- ditch. Photograph 6. V-ditch with downslope erosion undermining v-ditch. Typically caused by surface runoff running over v-ditch and not being diverted to run down the v-ditch. Areas with little or no vegetation Downslope erosion undermining v-ditch, typically caused by surface runoff running over v-ditch N Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Figure 3 Photograph 3. Area on east end of project with little or no vegetation exposing sandstone. Photograph 4. Area in center of project, just west of snack bar without vegetation and higher erosion. Exposes pebble conglomerate and sandstone at base of exposure. Slope with little or no vegetation and exposed sandstone Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Figure 3 Photograph 15. Horizontal crack in wall with drain line exiting center of wall, area east of snack bar. Photograph 16. Damage to top course of wall, note loose soil at top of wall along with vertical cut into bedrock at top of photograph indicating that wall was not built high enough or upper courses of block were removed. Damage at top of retaining wall. Visible loose soil and vertical cut into bedrock indicate that wall is not high enough or upper course(s) of block have been removed. MAX FIELD / RIENSTRA PARK Accessibility Study September 24, 2020 9 PROCESS Community Outreach The first community outreach meeting was an opportunity to discuss the project goals and scope with the community, answer questions about the project and allow a chance for open feedback. Comments from the community included a variety of topics. The discussion items have been summarized as items that are within the Measure P scope of work and those that are potential long term improvements that could be completed to further enhance the park, increase functionality and/or safety. In-Scope Improvements Ū Pedestrian bridge Ū Channel cleanup/restoration Ū Locking gates/controlled access Ū Trees and planting Ū Sidewalks around little league fields Ū Improved parking Ū Restore entrance/exit Out-of-Scope/Long-term Improvements Ū New concessions building Ū Extra bathrooms Ū Sports lights Ū Fencing Ū Safety lighting Ū Trails/pathways to transit station Ū Doggie bags Ū Accessible SDG&E trails Community Workshop #1 Community Workshop #1 MAX FIELD / RIENSTRA PARK Accessibility Study September 24, 2020 10 PLAN RECOMMENDATIONS Overall Plan (full size plan in Appendix A)N MAX AVELARKHAVEN DRSDG&E Parcel Potential Gravel Overflow Parking Netlon Overflow Parking E. ORANGE AVE Ball Field #1(ADA Field) Ball Field #2 Ball Field #3 Ball Field #4 Ball Field #5 Ball Field #6 Ball Field #7(Tee-ball) 1 2 3 4 5 6 Site Master Plan Concrete Asphalt Gravel Decomposed granite Ballfield turf Planting area Surrounding native planting Netlon Drainage Dugout Bleachers Structure Project Limit of Work Legend Phase 1 Phase 2 Phase 3 Legend Phasing planN The overall site plan illustrates park improvements, adjacencies, and the project limit of work. This master plan divides the site into 6 zones for more detailed discussion on the following pages. A full size plan with conceptual spot elevations can be found in Appendix A. Both short term and long term improvements are described in this document. Improvements in Phase 1 area are high priority areas around fields 1-4 and are in the most heavily utilized portion of the park. They consist primarily of ADA access, sidewalk upgrades, retaining wall construction and the new pedestrian bridge connection to the Loma Verde Recreation Center & Loma Verde Elementary School. Improvements in Phase 2 include upgrades to the south end of the park including new sidewalks, field upgrades to the smaller fields, a pedestrian connection to East Orange Avenue, and potential overflow parking lot access off the old access point from East Orange Avenue. Phase 3 consists of potential improvements on the SDG&E owned land and may include an overflow gravel parking lot (east of Max Ave,) enhanced trail connections, site amenities or program. Phase 3 also includes upgrades throughout the park that are not considered to be ADA or maintenance issues such as sports lighting, new concessions and/or restrooms. Loma Verde Recreation Center & Loma Verde Elementary School 120'60'0' SDG&E Parcel MAX FIELD / RIENSTRA PARK Accessibility Study September 24, 2020 11 PLAN RECOMMENDATIONS 1 2 3 4 5 6 7 8 1 7 5 9 Ball Field #2 10 N Site plan enlargement 11 12 Ball Field #1 (ADA Field)MAX AVE4 5 1 2 3 6 7 8 10 ADA parking stall reconfigured to meet City of Chula Vista Municipal Code requirements (see page 13 for parking layout enlargement) Realign existing fencing to allow a minimum five foot sidewalk around the ballfield New retaining walls, allowing for grade adjustments and soil retention Existing scoreboard to remain New CMU or cast-in-place concrete retaining walls at ramps and location of existing deteriorating retaining walls (see image 3 on page 12) Eliminate step between dugouts and adjacent walks/field (see image 2 on page 12) Adjust bleacher locations to allow minimum 5 foot wide circulation paths, with minimum 3 foot clearance at pinch points Seating area adjustments to allow clear path of travel ADA ramp with handrails (width varies: 8 - 11 feet wide, 1:12 maximum slope) New parking lot layout (see page 13) Cast-in-place concrete stairs with handrails and cheekwall, allowing circulation at approximately four feet of grade change. Directional signage to be located per ADA requirements. Existing channel / wetland Existing trail between Loma Verde Recreation Center / Loma Verde Elementary School and Max Ave Existing sewer pump station Existing V-ditch renovated for proper site drainage and to prevent future erosion 9 11 12 13 13 Zone 1 Site Improvements Legend 3LIMIT OF WORKLIMIT OF WORKLI M I T O F W O R K +164.25 +163.99 160.50+ 164.50+ +154.00 +156.50 PROPERTY LINEN Key plan 14 15 14 15 6 7 See page 13 for parking layout enlargement ZONE 6 MATCHLINE, SEE PAGE 19ZONE 2 MATCHLINE, SEE PAGE 14 156.50+ 163.25++161.00 +161.00 +164.00 2.8%1.5%1.6%8.1%60'30'0'PROPERTY LINE2 MAX FIELD / RIENSTRA PARK Accessibility Study September 24, 2020 12 PLAN RECOMMENDATIONS Zone 1 4. Stepping walkways between field #1 and #2 are to be replaced with compliant pathways. 3. A new ADA ramp with handrails and retaining walls will replace an existing staircase between Fields #1 and #2, where there currently is no equal accessible route. 2. Adjustments to site grades will remove the inaccessible step condition at dugout entries. 1. Improvements to Field #1 include paved accessible routes all the way around Field #1. This can be accomplished through adjustments to site grading and field fence locations. Existing Site Photos MAX FIELD / RIENSTRA PARK Accessibility Study September 24, 2020 13 PLAN RECOMMENDATIONS N ADA parking stalls Ball Field #2 Ball Field #1 (ADA Field) Ball Field #3 MAX AVEZone 1 - Parking Layout Enlargement Site Improvements A key goal of this study was to maximize parking capacity while also adjusting the layout to meet minimum stall size requirements. The existing parking lot contains 107 stalls. During our study of the existing lot, it was noted that the stall sizes were substandard and do not meet the requirements of the City of Chula Vista. By incorporating approximately half compact and half standard size stalls, the updated layout results in 102 parking spaces. This plan also looks at landscape enhancements in the parking lot. While it is not a requirement to meet Chula Vista Landscape Manual requirements, shade trees and planting areas are proposed where possible without impacting the number of available parking stalls. The parking layout option has 102 total parking stalls: Ū 51 standard parking stalls (10'x18') Ū 46 compact car parking stalls (9'x18') Ū 5 ADA parking stalls (includes 1 van accessible ADA parking stall) Compact car parking stalls (9'x18') ADA van parking N Key plan LIMIT OF WORK LIMIT OF WORK+161 +154 +152 Parking lot enlargement c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c 60'30'0' SDG&E utility enclosure Sewer pump station Biofiltration Bleachers PR O P E R T Y L I N E Trash enclosure area per City of Chula Vista standards Existing double head luminaire on wooden power pole 24' minimum drive aisle, to meet CVFD approval Existing fence realigned to allow 5' minimum sidewalk Final design to incorporate wheel stops or triangular curbs between parking and sidewalk EX EX EX EX PR PR PR PR PRPR PR PR Storm drain / headwalls Wheel stops or triangular curbs between parking lot and sidewalk SIDEWALK SIDEWALK Traditional wheel stops Paving pop-outs EX EX PR PR PR PR PR PR EX Existing Adjacent Trees 6 PR New Trees 14 New Planting Area 3,902 sf Parking Lot Landscape Enhancements MAX FIELD / RIENSTRA PARK Accessibility Study September 24, 2020 14 Van accessible ADA parking stall reconfigured to meet City of Chula Vista Municipal Code requirements (see page 13 for parking layout enlargement) ADA ramp with handrails (1:12 maximum slope) Existing SDG&E utility enclosure Remove posts and replace with new netting for foul ball protection (see image 2 on page 15) Eliminate step between dugouts and adjacent walks/field Adjust bleacher locations to allow for three feet minimum circulation clearance Seating area adjustments to allow clear path of travel Planted bioretention area to slow and filter run-off before it enters channel (see image 1 on page 15) New retaining walls, allowing for grade adjustments and soil retention New CMU or cast-in-place concrete retaining walls at location of existing deteriorating retaining walls along eastern end behind concessions Realign existing fencing to allow a minimum five foot sidewalk around ballfield Existing privately-owned concessions and existing restrooms with ADA access. Improvements to facilities will require coordination with City of Chula Vista and youth baseball leagues Existing informal trail between Loma Verde Recreation Center / Loma Verde Elementary School and Max Ave V-ditch renovated for proper site drainage and to prevent future erosion (see image 3 on page 15) Painted crosswalk with ADA curb ramps create dedicated pedestrian crossing through parking lot Prefabricated metal pedestrian bridge spanning channel (see image 4 on page 15) Five foot wide ADA accessible concrete trail between the park and Loma Verde Recreation Center / Loma Verde Elementary School 42" tall post-and-rail fence along the trail's east side provides fall protection (see image 5 on page 15) Trash enclosure per City of Chula Vista standards PLAN RECOMMENDATIONS 4 5 1 2 3 6 7 8 10 9 11 12 Ball Field #2 Ball Field #3 Zone 2 18 1516 7 5 Site Improvements Legend 4 5 1 2 3 6 7 8 10 9 11 12 13 14 15 16 17 17 6 5 N Site plan enlargement LIMIT OF WORKLIMIT OF WORK+154 +154 +153 +156.5 +152 +154 +153.8 PROPERTY LINEPROPERTY LINEN Key plan ZONE 1 MATCHLINE, SEE PAGE 11 ZONE 3 MATCHLINE, S E E P A G E 1 6 1.5%4.5%18 5 6 6 6 12 12 13 14 9 9 1.4% 1.63 % 1.0% 60'30'0' 19 20 19 Existing double head luminaire on wooden power pole Storm drain and headwalls to allow stormwater flow below parking lot21 Existing channel and wetland delineation Existing scoreboard 22 23 23 22 20 21 MAX FIELD / RIENSTRA PARK Accessibility Study September 24, 2020 15 PLAN RECOMMENDATIONS Zone 2 2. Non-compliant circulation clearances at the concessions area are remediated by removing posts and using netting for foul ball protection. 1. Planted biofiltration basin at existing drainage inlet will reduce erosion impacts and remediates steep drop-off surrounding non-compliant walkways. 5. 42 inch tall post-and-rail fence alongside paved trail to Loma Verde Recreation Center & Loma Verde Elementary School. 4. Prefabricated metal pedestrian bridge spanning channel, with concrete abutments outside of the stream channel Existing Site Photos Proposed Site Elements 3. Replacement of existing damaged V-ditch will prevent further erosion. MAX FIELD / RIENSTRA PARK Accessibility Study September 24, 2020 16 PLAN RECOMMENDATIONS Zone 3 N Site plan enlargement Ball Field #4 New retaining walls, allowing for grade adjustments and soil retention Eliminate step between dugouts and adjacent walks/field Adjust bleacher locations to allow for three feet minimum circulation clearance Seating area adjustments to allow clear path of travel Existing privately-owned concessions and existing restrooms with ADA access. Improvements to facilities will require coordination with City of Chula Vista and youth baseball leagues New concrete walkway extends south connecting to overflow parking lot and East Orange Avenue Existing channel and wetland Five foot wide ADA accessible concrete trail between the park and Loma Verde Recreation Center / Loma Verde Elementary School 42" tall post-and-rail fence along the trail's east side provides fall protection (see image 5 on page 15) V-ditch renovated for proper site drainage and to prevent future erosion (see image 3 on page 15) Existing scoreboard 4 5 1 2 3 6 7 8 Ball Field #3 1 2 3 5 6 7 8 4 4 LIMIT OF WORK+152 +154 +152 +150.8 N Key plan PROPERTY LINEPROPERTY LINESite Improvements Legend ZONE 2 MATCHLINE, S E E P A G E 1 4 ZONE 4 MATCHLI N E , S E E P A G E 1 7 9 10 2 3 5 9 10 1.5%1.5%10 60'30'0' 11 11 MAX FIELD / RIENSTRA PARK Accessibility Study September 24, 2020 17 PLAN RECOMMENDATIONS N Site plan enlargement Zone 4 Ball Field #5 Ball Field #4 Ball Field #6 New concrete walkway extends south connecting to overflow parking lot and East Orange Avenue New concrete paving is expanded west behind home plate to create continuous paved surface to dugouts Seating area adjustments to allow clear path of travel Eliminate step between dugouts and adjacent walks/field Adjust bleacher locations to allow for three feet minimum circulation clearance Existing channel and wetland Five foot wide ADA accessible concrete trail between the park and Loma Verde Recreation Center / Loma Verde Elementary School 42" tall post-and-rail fence along the trail's east side provides fall protection (see image 5 on page 15) 4 5 1 2 3 6 4 6 5 3 2 LIMIT OF WORKLIMIT OF WORK+144 +148 +149 +150.8 PROPERTY LINEN Key plan Site Improvements Legend ZONE 3 M A T C H L I N E , S E E P A G E 1 6 ZONE 5 MATCHLINE, SEE PAGE 18 7 8 1 4 4 4 7 8 1.6%1.0%60'30'0' MAX FIELD / RIENSTRA PARK Accessibility Study September 24, 2020 18 PLAN RECOMMENDATIONS N Site plan enlargement Zone 5 Ball Field #6 Ball Field #7 (Tee-ball) Netlon Overflow ParkingLegend (69 stalls) E. ORANGE AVE New concrete walkway extends south connecting to overflow parking lot and East Orange Ave. New barrier arm gate at existing entrance Overflow parking for 69 18’ x 10’ stalls Existing channel and wetland Cast-in-place concrete staircase with handrails for shortcut connection to East Orange Ave. (optional) Chainlink fence reconfigured for pedestrian access, with new fence and optional locking gate 1 2 3 4 4 1 2 3 Netlon system with event parking Netlon system cross-section reinforced lawn root zone with sand, soil and fiber sub-base compacted sub-grade grass LIMIT OF WORKLIMIT OF WORKLIMIT OF WORK 147.0+ +146 +145 +144 PROPERTY LINEN Key plan Site Improvements The following long-term improvements are proposed in Zone 5: Ū A 24,000 square foot overflow lot on the southwestern portion of the site accommodates approximately 69 additional parking stalls. Ū The parking lot is to be paved with Netlon Advanced Turf system, a load- bearing natural grass reinforced surface. This permeable system allows for flexibility as the site can be used for overflow parking or continued use of ball field #7. ZONE 4 MATCHLINE, SEE PAGE 17 1.0%1.0% 1 60'30'0' 5 5 6 6 MAX FIELD / RIENSTRA PARK Accessibility Study September 24, 2020 19 PLAN RECOMMENDATIONS N Site plan enlargement Zone 6 Legend Flashing rapid beacon push-button crosswalk Painted crosswalk with ADA curb ramps 16,000 square foot gravel parking lot with potential for 50 stall capacity; Higher capacity could be achieved if major earthwork was performed. Provide wood pole / header to demarcate parking stall layout at 10' O.C. Existing barrier arm gate Existing trail between Loma Verde Recreation Center / Loma Verde Elementary School and Max Avenue Existing informal trails 1 2 3 12 3 4MAX AVE Rapid beacon push button crosswalk Potential Gravel Parking (50 stalls) PROPER T Y LI N E PROPER T Y LI N E N Key plan 60'30'0'ZONE 1 MATCHL INE , SEE PAGE 11 4 5 6 5 6 6 Site Improvements The following long-term improvements are proposed in Zone 6. The potential gravel lot is proposed on land currently owned by SDG&E and would require coordination and an agreement negotiated with SDG&E. Additional traffic analysis and/or a study may be required to evaluate additional pedestrian safety improvement should be considered for the mid-block crossing. Potential improvement for consideration may include bulbouts, adding a pedestrian refuge island, or adding enhanced paving in the crosswalk. APPENDIX A Full Size Plan B Cost Estimate C Geotechnical Report D Biological Memo MAX FIELD / RIENSTRA PARK Accessibility Study September 24, 2020 CCCCCCCCCCCCCC C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C CB L E A C H E R S BLEACH ERS BLEACHERS BL E A C H E R S BLEAC H E R S BLEACHERSDUGOUTDUG O U T DUGOUTDUGOUT D U G O U T DUGOUTB L E A C H E R S BLEACHERSBLE A C H E R S CON C E S SI O N S DUGOUTCON C E S SI O N S RES T R O O M S U T I L I T Y E N C L O S U R E STRUCTUREDUG O U T B L E A C H E R S DUGOUT DUGOUTBLEACHERS DUGOUTDUGOUT VANMAX AVENUESITE RENNOVATION RECOMMENDATIONS E ORANGE AVENUE LOMA VERDE RECREATION CENTER & LOMA VERDE ELEMENTARY SCHOOL LARKHAVEN DRAPPENDIX A MAX FIELD/ RIENSTRA PARK - SITE MASTER PLAN Accessibility Study September 21, 2020 Granite Asphalt Gravel Decomposed granite Ballfield turf Planting area Surrounding native planting Netlon Channel Dugout Bleachers Structure Project Limit of WorkMAX FIELD/ RIENSTRA PARK - SITE MASTER PLAN Accessibility Study September 21, 2020 Netlon Overflow Parking Ball Field #6 Ball Field #5 Ball Field #4 Ball Field #3 Ball Field #2 Ball Field #1 (ADA Field) Ball Field #7 (Tee-ball)LARKHAVEN DRE. ORANGE AVE MAX AVEPotential Gravel Overflow Parking SDG&E Parcel Loma Verde Recreation Center & Loma Verde Elementary School SDG&E Parcel APPENDIX A Max Field/Rienstra Park Accessibility Feasibility Study 9/19/2020 PRELIMINARY CONSTRUCTION COST 1.0 Site Improvement Items Item No. Location/Description Quantity Unit Unit Cost Cost Onsite Park Improvements - ADA 1 ADA Ramps & Handrails 1,052 SF $25.00 $26,300 2 Cast In Place Stairs and Cheek walls w/ Handrails 80 SF $100.00 $8,000 3 Retaining Wall & Footing-height varies-to level out areas for accessibility 1,980 SF $49.00 $97,020 4 Concrete Paving - std. gray broom finish (Ballfield and parking lot areas)36,558 SF $12.00 $438,696 5 Concrete Paving - std. gray broom finish (connection to East Orange Ave)4,168 SF $12.00 $50,016 6 Grinding for Removal of striping 1,080 LF $2.55 $2,754 7 Grind & Overlay (portion of parking lot to make accessible)10,000 SF $4.00 $40,000 8 Trees, Vegetation and Irrigation 1 LS $60,000.00 $60,000 9 AC Slurry Seal 50,000 SF $0.99 $49,500 10 Parking Lot Striping (102 parking stalls)1,080 LF $1.09 $1,177 11 Dugouts - remove steps and replace benches (to make accessible)12 EA $5,000.00 $60,000 12 Upgrades to Accessibility for Restroom/Concession Buildings*1 Allowance $50,000.00 $50,000 13 Stair access from East Orange Avenue @ Field #7 120 SF $100.00 $12,000 14 Site Revegetation and Irrigation Repair 1 LS $20,000.00 $20,000 SUBTOTAL $915,463 $1,318,267 Onsite Park Improvements - Failing Infrastructure 15 Railing 500 LF $28.00 $14,000 16 Temporary Shoring 2,610 SF $20.00 $52,200 17 Retaining Wall Replacement (Footing & Wall & Backfill & Drains)2,610 SF $39.00 $101,790 18 V-Ditch Replacement (New Ditch & R&R)500 LF $25.00 $12,500 19 Revegetation of Barren Slope Areas 11,100 SF $0.75 $8,325 20 Erosion Control/Slope Surface Stabilization (Hydroseed)13,300 SF $0.50 $6,650 SUBTOTAL $195,465 $281,470 Pedestrian Bridge & Accessible Path & Railing (for access to Loma Verde Rec Center) 21 Pedestrian Bridge (Per separate Cost Estimate)1 LS $148,069.00 $148,069 22 Concrete (std. gray broom finish) or DG Pathway - (connection to Rec Center)4,300 SF $12.00 $51,600 23 42" Tall Post and Rail Fence 860 LF $40.00 $34,400 24 Grading for Pathway 400 CY $30.50 $12,200 25 Subgrade Prep 4,300 SF $0.44 $1,892 26 Erosion Control 1 LS $5,000.00 $5,000 SUBTOTAL $253,161 $364,552 Field #7 Parking Lot - Optional 27 Netlon Reinforced Turf Parking Area (base, drainage only - doesn't include turf)23,500 SF $20.00 $470,000 28 Turf at Netlon area 23,500 SF $2.00 $47,000 SUBTOTAL $517,000 $744,480 Overflow Parking Lot East of Max Avenue - Optional 29 Overflow gravel parking lot 16,000 SF $2.00 $32,000 30 Wheel stops (Wooden Posts)500 LF $10.00 $5,000 31 Flashing Rapid Beacon Push Button Crosswalk 1 LS $35,000.00 $35,000 32 Crosswalk paving and striping 1 LS $1,000.00 $1,000 SUBTOTAL $73,000 $105,120 Onsite Park Improvements - Optional 33 Site furnishings 1 Allowance $25,000.00 $25,000 34 New Vehicular Entrance Gate 1 Allowance $10,000.00 $10,000 SUBTOTAL $35,000 $50,400 SUBTOTAL CONSTRUCTION COSTS (ALL CATEGORIES)$1,989,089 MOBILIZATION 3%$59,673 DESIGN, SURVEY & CONTRACT ADMINISTRATION 15%$298,363 CONSTRUCTION INSPECTION 6%$119,345 CONTINGENCIES 20%$397,818 TOTAL PARK IMPROVEMENTS COST $2,864,288 TOTAL THIS CATEGORY (INCLUDES ITEMS/CONTINGENCIES NOTED BELOW,44%) TOTAL THIS CATEGORY (INCLUDES ITEMS/CONTINGENCIES NOTED BELOW,44%) TOTAL THIS CATEGORY (INCLUDES ITEMS/CONTINGENCIES NOTED BELOW,44%) TOTAL THIS CATEGORY (INCLUDES ITEMS/CONTINGENCIES NOTED BELOW,44%) TOTAL THIS CATEGORY (INCLUDES ITEMS/CONTINGENCIES NOTED BELOW,44%) TOTAL THIS CATEGORY (INCLUDES ITEMS/CONTINGENCIES NOTED BELOW,44%) *This cost does not include improvements to structures. These structures are privately owned and managed by Southbay Little League (SBLL). Any future improvements to structures to be coordinated between City of CV & SBLL S P U R L O C K L a n d s c a p e A r c h i t e c t s GEOTECHNICAL INVESTIGATION OF SLOPE EROSION AND RETAINING WALL DAMAGE MAX FIELD RIENSTRA PARK 300 MAX AVENUE CHULA VISTA, CA for City of Chula Vista Department of Public Works 276 Fourth Ave Chula Vista, CA 91910 June 19, 2020 20-0287-01 APPENDIX C Carson 310.684.4854 | Concord 925.243.6662 | Rancho Cucamonga 909.989.1751 Sacramento 916.631.7194 | San Diego 858.609.7138 | San Jose 408.362.4920 June 19, 2020 City of Chula Vista Department of Public Works 276 Fourth Ave Chula Vista, CA 91910 Attention: Patrick Moneda, Senior Civil Engineer Subject: Geotechnical Investigation of Slope Erosion and Retaining Wall Damage Max Field Rienstra Park 300 Max Avenue Chula Vista, CA Dear Mr. Moneda: In accordance with your request, a geotechnical investigation has been completed for the above referenced project. The report addresses both engineering geologic and geotechnical conditions. The results of the investigation are presented in the accompanying report, which includes a description of site conditions, results of our field exploration, laboratory testing, conclusions, and recommendations. We appreciate this opportunity to be of continued service to you. If you have any questions regarding this report, please do not hesitate to contact us at your convenience. Respectfully submitted, RMA Group Ken Dowell, PG, CEG Project Geologist CEG 2470 Jorge Meneses, PhD, PE, GE, D.GE, F. ASCE Principal Geotechnical Engineer GE 3041 Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page i TABLE OF CONTENTS PAGE 1.00 INTRODUCTION 1 1.01 Purpose 1 1.02 Scope of the Investigation 1 1.03 Site Location and Description 1 1.04 Site Observations 2 1.05 Investigation Methods 2 2.00 FINDINGS 3 2.01 Geologic Setting 3 2.02 Earth Materials 3 2.03 Surface and Groundwater Conditions 3 2.04 Faults 3 2.05 Historic Seismicity 4 2.06 Landslides 4 3.00 CONCLUSIONS AND RECOMMENDATIONS 4 3.01 General Conclusion 4 3.02 General Earthwork and Grading 5 3.03 Slope Remediation 5 3.04 Faulting 6 3.05 Seismic Design Parameters 6 3.06 Liquefaction and Secondary Earthquake Hazards 7 3.07 Retaining Wall Foundations 8 3.08 Miscellaneous Concrete Flatwork 8 3.09 Footing Excavation and Slab Preparations 8 3.10 Lateral Load Resistance 9 3.11 Drainage and Moisture Proofing 10 3.12 Plan Review 10 3.13 Geotechnical Observation and Testing 10 4.00 CLOSURE 11 Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page ii TABLE OF CONTENTS (Continued) PAGE FIGURES AND TABLES Figure 1 Site Location Map Figure 2 Regional Geologic Map Figure 3 Site Photographs Table 1 Notable Faults within 100 Km Table 2 Historical Strong Earthquakes APPENDICES Appendix A Laboratory Tests B1 Appendix B General Earthwork and Grading Specifications C1 Appendix C References D1 Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page 1 1.00 INTRODUCTION 1.01 Purpose A geotechnical investigation of slope erosion and retaining wall damage has been completed for the slope and retaining wall on the south side of Max Field at Rienstra Park in Chula Vista, California. The purpose of the investigation was to observe and summarize geotechnical and geologic conditions at the site and also the condition of the existing masonry retaining wall and slope, and to provide geotechnical and engineering geologic design parameters. 1.02 Scope of the Investigation The general scope of this investigation included the following: • Review of published and unpublished geologic, seismic, groundwater and geotechnical literature. • Examination of aerial photographs. • Logging, sampling and backfilling of 2 shallow exploratory borings excavated with a hand auger. • Laboratory testing of representative soil samples. • Geotechnical evaluation of the compiled data. • Preparation of this report presenting our findings, conclusions and recommendations. Our scope of work did not include a preliminary site assessment for the potential of hazardous materials onsite. 1.03 Site Location and Description The subject retaining wall and slope are located on the south side of Max Field at Rienstra Park in the City of Chula Vista, California. The retaining wall and slope are bounded by baseball fields to the north, residential properties to the south, Max Avenue to the east. The slope and retaining wall extends about 750 feet to the west and southwest from Max Avenue. Limits of the investigation are shown on Figure 1 Elevations at the toe of the slope range from 145 to 165 feet above sea level and elevations at the top of the slope range from 180 to 200 feet above sea level. The gradient ranges from 3:1 (horizontal to vertical) on the west end of the project to 5:1 (horizontal to vertical) on the east end of the project. The slope is vegetated with native shrubs and annual grasses and a few large eucalyptus trees (Photographs 1 and 2). A concrete v-ditch is located on the slope (Photograph 2) and the slope is not irrigated. The slope does have a few local areas devoid of vegetation (these areas are indentified on Figure 1) (Figures 3 and 4). The masonry retaining wall located at the base of the slope ranges from 2 to about 7-8 feet in height and based on historic aerial photographs was constructed in the 1960’s. The wall is painted, appears to have had modifications completed in the past and has several cracks and has areas that are locally bulging outward (Photographs 8, 11, 12 and 14). A concrete sidewalk is located at the base of the wall. A concrete staircase is located about 120 feet west of Max Avenue and is about 8 feet in height. Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page 2 1.04 Site Observations The slope is made up of a peddle conglomerate and sandstone sedimentary bedrock of the San Diego Formation (Figures 3 and 4). These bedrock units are fairly young (early Pleistocene to late Pliocene) about 850,000 to 3 million years old and are not well cemented and are made up of mainly sand. They are subject to erosion that creates the loose colluvial soil that then can move down slope due to gravity and surface runoff. This is particularly evident in the areas where there is no vegetation. Over time the bedrock units have eroded and that subsequent soil has moved downslope through natural processes. The slope itself appears stable, at its steepest it is 3:1 (horizontal to vertical and ranges from 3.5:1 to 5:1 where the retaining wall occurs. There are not indications of deep slope failure just typical surficial instability where vegetation has not regrown to protect the surface of the slope from erosion. The slope is vegetated with bushes and wild grasses and it does not have an irrigation system to promote growth of more permanent vegetation. Further there are numerous ground squirrel burrows on the slope, due to their digging actions this create loose soil and accelerates erosion of the slope face The concrete v-ditch dates to the construction of the retaining wall and baseball fields in the mid-1960’s and is in poor condition (Photographs 2, 5, 6, 7, 8) . While it is not clogged with soil or vegetation, it is cracked and some areas runoff has either overtopped the v-ditch or run under it, eroding the downslope side of the v-ditch and allowing water to even run underneath it in places. The masonry retaining wall (Photographs 9 – 16) appears to be solid grouted is solid grouted at least all of the exposed cells at the top of the wall and those areas exposed during prior modifications are filled with grout. It does have open joints on the first course to allow drainage, but a majority of them have been covered, or partially covered, by pavement (Photograph 10). The soil behind the wall is at the top of the wall or overtopping the wall and in some locations soil is being held back by boards on top of the wall. Behind the wall in some areas the bedrock is exposed in verticals typically less than 1 foot in height, however, this could be an indicator that other modification have taken place, such as lowering of the wall by removing the upper course of block (Photographs 9, 11, 14, 16). East of the snack bar the wall has a horizontal crack and an area is bulging outward (Photographs 15 and 16). Near this area, the wall looks like it was modified to allow for more bleacher space and is also bulging outward (Photographs 11-13). Also in this area is a section where you can see behind the wall. A drain was not visible behind the wall. In this area the footing is exposed and only looks to the about 3-4” thick (this is the area that looks to have been modified at one time). Another modified section is located to the west of the press box and it too is bulging outward (Photograph 14). At the end of the v-ditch, behind the bathroom building the wall has been extended higher with dry stacked block above the retaining wall. Overall the condition of the wall is very poor. It is almost 55-60 years old, the cement in the block appears to have started to deteriorate; probably due to the elevated salt levels in the air; by a lack of a drain behind the wall, and previous modifications to the wall and the pressure being exerted on the wall by the bushes growing on the slope are all conditions leading to the deterioration of the wall. 1.05 Investigation Methods Our investigation consisted of office research, field exploration, laboratory testing, review of the compiled data, and preparation of this report. It has been performed in a manner consistent with generally accepted engineering and geologic principles and practices, and has incorporated applicable requirements of California Building Code. Definitions of technical terms and symbols used in this report include those of the ASTM International, the California Building Code, and commonly used geologic nomenclature. Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page 3 Technical supporting data are presented in the attached appendices. Appendix A presents a description of our laboratory testing and the test results. Standard grading specifications and references are presented in Appendices B and C, respectively. 2.00 FINDINGS 2.01 Geologic Setting The site is located on the western side of the Peninsular Ranges geomorphic province. The Peninsular Ranges are one of the largest geologic provinces in the North America, extending from Los Angeles to the tip of Baja California. Much of the Peninsular Ranges is composed of intrusive, granitic rocks. Within the coastal San Diego region, the granitic is overlain by Pleistocene age and older sedimentary units. The project site is underlain by mainly colluvium and sedimentary bedrock consisting of sandstone and pebbly conglomerate of the early Pleistocene to late Pliocene. A regional geologic map of the area (Figure 2) indicates that the site is underlain by Pleistocene age sedimentary bedrock. 2.02 Earth Materials Our investigation encountered colluvium and sedimentary bedrock. Colluvium is soil deposited mainly by gravity and water runoff typically at the base or face of a slope. Colluvium is typically loose. The colluvium encountered at the site was light brown to gray in color and derived from the erosion of the sedimentary bedrock. The sedimentary bedrock encountered at the site has been regionally mapped at part of the San Diego formation. The bedrock exposed at the site consists of a yellowish-brown to gray, fine to medium grained sandstone and reddish-brown pebble and cobble conglomerate that is poorly indurated and poorly cemented. The sandstone was found to be dense and the conglomerate was very dense. Two hand auger boring were attempted at the site and both achieved refusal at depths between 3 ½ feet to 5 feet, mainly due to encountering the gravel and cobbles of the conglomerate. Regional mapping and our site mapping indicate that the bedding in the bedrock generally slopes to the south to southwest at very shallow angles (regional mapping indicated a dip of the bedding at 3-4 degrees to the southwest, our site mapping indicated that the bedrock dips about 3 to 5 degree to the south to southwest). The dip of the bedrock is into, or neutral to, the existing slope face. 2.03 Surface and Groundwater Conditions No areas of ponding or standing water were present or observed on or at the base of the slope at the time of our study. Further, no springs or areas of natural seepage were found on the slope. Groundwater was not encountered in our borings. 2.04 Faults The site is not located within the boundaries of an Earthquake Fault Zone for fault-rupture hazard as defined by the Alquist-Priolo Earthquake Fault Zoning Act and no faults are known to pass through the property. The nearest Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page 4 Earthquake Fault Zone is located about 8 miles to the west of the site along the Silver Strand branch of the Rose Canyon fault. The nearest mapped fault to the site is parts of the La Nacion Fault Zone, located about 1 mile to the east at its closest location. The last motion along the fault zone is estimated to be Quaternary aged or more than 10,00o years ago. The fault zone is not considered active by the State of California. The distance to notable faults within 100 kilometers of the site is presented on Table 1. 2.05 Historic Seismicity The nearest large historic earthquake in the vicinity of the site was the magnitude 5.4 Oceanside earthquake of 1986 which was approximately 51 miles northwest of the site. Strong earthquakes that have occurred in this region in historic time and their approximate epicentral distances are summarized in Table 2. Our research of regional geologic and seismic data did not reveal any known instances of ground failure within the site associated with regional seismic activity. Seismic design parameters relative to the requirements of the 2019 California Building Code are presented in Section 3.05. 2.06 Landslides Landslides were not observed during our investigation of the slope. Topographic landforms suggestive of landslides were not apparent in the field or on aerial photographs. The existing slope does have local areas of surficial failure. Investigation of these areas during our site visit indicated that these were very shallow features that were only a few thick and most likely caused by erosion from water running down the face of the slope and loose colluvium on the face of slope. These areas were also devoid of vegetation. Regional geologic and landslide hazard maps do not map any landslides within the site. 3.00 CONCLUSIONS AND RECOMMENDATIONS 3.01 General Conclusions Based upon our site visit and information gathered we would recommend the following general recommendations for the slope. The v-ditch should be reconstructed to current standards, place some temporary stabilization methods on the slope particularly in the areas where the erosion has occurred with some minor work to lower any areas over steepened from erosion, install an irrigation system and hydro seed the slope to promote sustainable vegetation to protect the slope from surface erosion. There are also a lot of ground squirrel burrows, especially in the lower part of the slope, which adds to the erosion. A program should be instituted to limit the burrows on the slope. Additional information for remediation of the slope is provided in Section 3.03. Due to the age and condition of the existing retaining wall, we would recommend that it be removed and reconstructed using current standards and materials including clearing away the bushes within 5 feet of the top of the wall to prevent pressure being applied to the backside of the new wall, removing the loose soil behind the top of the wall and construction a v-ditch at the top of the wall to divert runoff to drainage inlets and not into Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page 5 the soil behind the wall and collect soil carried by the runoff. Additionally, a maintenance program for the site should include removal of loose soil from the v-ditch at the top of the wall. Additional information for design of retaining wall is included in Section 3.11. 3.02 General Earthwork and Grading Any grading should be performed in accordance with the General Earthwork and Grading Specifications outlined in Appendix C, unless specifically revised or amended below. Recommendations contained in Appendix C are general specifications for typical grading projects and may not be entirely applicable to this project. It is also recommended that all earthwork and grading be performed in accordance with Appendix J of the 2019 California Building Code and all applicable governmental agency requirements. In the event of conflicts between this report and Appendix J, this report shall govern. 3.03 Slope Remediation Based upon our review of the current slope conditions, it is our opinion that the existing slope is structurally stable and no indications of active or former slippage or sliding (such as fissures or earth cracks, large areas of slumped soil, diversion of the existing v-ditch) is evident, the surface of the slope is undergoing the natural erosion processes created by gravity and surface water runoff. Disruption of surface water runoff and stabilization of the surficial face of the slope will limit the downslope erosion of the slope face. Remediation of the slope should include the items listed in Section 3.01. The slope currently is covered with annual grasses and chaparral bushes and a few large trees. The annual grasses do provide some measure of stabilization for the slope but only when they are actively growing, once their growth cycle is complete and the plants die they no longer provide stability to the surface of the slope and can typically accelerate erosion of the surface soils during rain storm in the non-growing season due to loosened soil in the root zone or upper few inches of soil. We would recommend that slope be hydroseeded with a more permanent vegetation mix that will provide year round stability for the slope. This may also include installation of a permanent irrigation system. A landscape architect could be consulted to determine the best hydroseed mix for the area In the areas where vegetation is mainly the grasses or thin or lacking vegetation the surface of the slope may be stabilized using materials such as jute mesh and straw waddles to slow the movement of water and soil down the slope face. The three areas indicated on Figure 1 where the vegetation is scarce or absent also has locally steepened slope faces due to erosion in these areas. Loose soil from these areas should be removed and the slope face returned to match the existing surrounding slope faces. This should be accomplished using compacted fill soil. To promote the growth of vegetation in these areas the fill soil should not be compacted to more than 85% relative compaction and the face of these areas should be covered with jute mesh and straw waddles placed upslope from them to limit surface water runoff. The existing v-ditch should be removed and a new drainage system installed to current City standards. It should be designed by a civil engineer to provide positive drainage off the slope into an appropriately sized drainage system. Further, a maintenance program should be installed that include cleaning the v-ditch of soil, filling cracks in the v- ditch and repairing areas of erosion around the v-ditch. An annual maintenance program that would include inspection, repair and cleaning of the v-ditch, repair of any Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page 6 future surficial failures and maintenance of good surface vegetation should be implemented. 3.04 Faulting Since the site is not located within the boundaries of an Earthquake Fault Zone and no faults are known to pass through the property, surface fault rupture within the site is considered unlikely. 3.05 Seismic Design Parameters The potential damaging effects of regional earthquake activity must be considered in the design of structures. Mapped seismic design parameters have been developed in accordance with Section 1613 of the 2019 California Building Code (CBC) using the online U.S. Geological Survey Seismic Design Maps Calculator (ASCE 10 Standard), a site location based on latitude and longitude, and site characterization as Site Class C based on our preliminary geotechnical investigation. The parameters generated for the subject site are presented below: 2019 California Building Code (CBC) Seismic Parameters Parameter Value Site Location Latitude = 32.60333 degrees Longitude = -117.04615 degrees Site Class Site Class = C Soil Profile Name = Very dense soil and soft rock Mapped Spectral Accelerations (Site Class B) Ss (0.2- second period) = 0.946g S1 (1-second period) = 0.326g Site Coefficients (Site Class C) Fa = 1.2 Fv = 1.5 Risk-Targeted Maximum Considered Earthquake Spectral Accelerations (Site Class C) SMS (0.2- second period) = 1.135g SM1 (1-second period) = 0.49g Risk-Targeted Design Earthquake Spectral Accelerations (Site Class C) SDS (0.2- second period) = 0.757g SD1 (1-second period) = 0.326g The above table shows that the mapped spectral response acceleration parameter a 1-second period (S1) < 0.75g. Therefore, for Risk Categories I, II and III the Seismic Design Category is D and for Risk Category IV the Seismic Design Category is D (CBC Table 1604.5 and Section 1613.3.5). Consequently, as required for Seismic Design Categories C through F by CBC Section 1803.5.11, slope instability, liquefaction, total and differential settlement, and surface displacement by faulting or seismically lateral spreading or lateral flow should be addressed. The above table shows that the mapped spectral response acceleration parameter a 1-second period (S1) < 0.75g and spectral response acceleration parameters are SDS ≥ 0.50g and SD1 ≥ 0.20g. Therefore, the Seismic Design Category has been determined from Tables 1613.3.5(1) and 1613.3.5(2) using a Risk Category of I, II, II and/or IV is D for all Risk Categories (CBC Section 1613.5.6). Consequently, as required for Seismic Design Categories C Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page 7 through F by CBC Section 1803.5.11, slope instability, liquefaction, total and differential settlement, and surface displacement by faulting or seismically lateral spreading or lateral flow have been evaluated. Applicable portions of CBC Section 1803.5.12 have also been evaluated including dynamic lateral loading of retaining walls. Peak earthquake ground acceleration adjusted for site class effects (PGAM) has been determine in accordance with ASCE 7-10 Section 11.8.3 as follows: PGAM = FPGA x PGA = 0.417g x 1.2 = 0.500g. 3.06 Liquefaction and Secondary Earthquake Hazards Potential secondary seismic hazards that can affect land development projects include liquefaction, tsunamis, seiches, seismically induced settlement, seismically induced flooding and seismically induced landsliding. Liquefaction Liquefaction is a phenomenon where earthquake-induced ground motions increase the pore pressure in saturated, granular soils until it is equal to the confining, overburden pressure. When this occurs, the soil can completely lose its shear strength and enter a liquefied state. The possibility of liquefaction is dependent upon grain size, relative density, confining pressure, saturation of the soils, and intensity and duration of ground shaking. In order for liquefaction to occur, three criteria must be met: underlying loose, coarse-grained (sandy) soils, a groundwater depth of less than about 50 feet, and a potential for seismic shaking from nearby large-magnitude earthquake. Due to shallow sedimentary bedrock beneath the site, soil liquefaction at the site is unlikely and liquefaction calculations were not performed. Tsunamis and Seiches Tsunamis are sea waves that are generated in response to large-magnitude earthquakes. When these waves reach shorelines, they sometimes produce coastal flooding. Seiches are the oscillation of large bodies of standing water, such as lakes, that can occur in response to ground shaking. Tsunamis and seiches do not pose hazards due to the inland location of the site and lack of nearby bodies of standing water. Seismically Induced Settlement Seismically induced settlement occurs most frequently in areas underlain by loose, granular sediments. Damage as a result of seismically induced settlement is most dramatic when differential settlement occurs in areas with large variations in the thickness of underlying sediments. Settlement caused by ground shaking is often non-uniformly distributed, which can result in differential settlement. Based upon the shallow bedrock beneath the site, settlement caused by ground shaking is estimated to be minimal. Seismically Induced Flooding The site is not located within a potential dam inundation area. In addition, there are no up gradient water reservoirs or dams located in close proximity of the site. Consequently seismically induced flooding at the site is unlikely. Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page 8 Seismically Induced Landsliding According to the California Geological Survey Landslide Inventory (https://maps.conservation.ca.gov/cgs/lsi/app/), there are no mapped landslides within the project area. Based upon the general geologic structure of the sedimentary bedrock the makes up the subject slope, particularly the low dip angle of less than 5° and the into slope or neutral direction of the dip relative to the slope face, landsliding due to seismic events is unlikely. 3.07 Retaining Wall Foundations Isolated spread footings and/or continuous wall footings are recommended to support the proposed structures. Footings should be established in firm bedrock or two feet of compacted fill materials 90% relative compaction. If footings transition from being founded in bedrock to being founded on fill and construction joint should be placed where the transition occurs to limit differential settlement. Footings may be designed using the following allowable soil bearing values: Retaining Wall Footings: Footings for retaining walls should be founded a minimum depth of 12 inches and have a minimum width of 12 inches. Footings may be designed using the allowable bearing capacity and lateral resistance values recommended for building footings. However, when calculating passive resistance, the upper 6 inches of the footings should be ignored in areas where the footings will not be covered with concrete flatwork. This value may also be increased by 8% for each additional foot of width or depth to a maximum value of 3,000 psf. Reinforcement should be provided for structural considerations as determined by the design engineer. The above bearing capacities represent an allowable net increase in soil pressure over existing soil pressure and may be increased by one-third for short-term wind or seismic loads. The maximum expected settlement of footings designed with the recommended allowable bearing capacity is expected to be on the order of ½ inch with differential settlement on the order of ¼ inch. 3.08 Miscellaneous Concrete Flatwork Miscellaneous concrete flatwork and walkways may be designed with a minimum thickness of 4 inches. Large slabs should be reinforced with a minimum of 6x6-10/10 welded wire mesh placed at mid-height in the slab. Control joints should be constructed to create squares or rectangles with a maximum spacing of 15 feet. Walkways may be constructed without reinforcement. Walkways should be separated from foundations with a thick expansion joint filler. Control joints should be constructed into non-reinforced walkways at a maximum of 5 feet spacing. The subgrade soils beneath all miscellaneous concrete flatwork should be compacted to a minimum of 90 percent relative compaction for a minimum depth of 12 inches. The geotechnical engineer should monitor the compaction of the subgrade soils and perform testing to verify that proper compaction has been obtained. 3.09 Footing Excavation and Slab Preparations All footing excavations should be observed by the geotechnical consultant to verify that they have been excavated Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page 9 into competent soils. The foundation excavations should be observed prior to the placement of forms, reinforcement steel, or concrete. These excavations should be evenly trimmed and level. Prior to concrete placement, any loose or soft soils should be removed. Excavated soils should not be placed on slab or footing areas unless properly compacted. Prior to the placement of the moisture barrier and sand, the subgrade soils underlying the slab should be observed by the geotechnical consultant to verify that all under-slab utility trenches have been properly backfilled and compacted, that no loose or soft soils are present, and that the slab subgrade has been properly compacted to a minimum of 90 percent relative compaction within the upper 12 inches. Footings may experience and overall loss in bearing capacity or an increased potential to settle where located in close proximity to existing or future utility trenches. Furthermore, stresses imposed by the footings on the utility lines may cause cracking, collapse and/or a loss of serviceability. To reduce this risk, footings should extend below a 1:1 plane projected upward from the closest bottom of the trench. Slabs on grade and walkways should be brought to a minimum of 2% and a maximum of 6% above their optimum moisture content for a depth of 18 inches prior to the placement of concrete. The geotechnical consultant should perform insitu moisture tests to verify that the appropriate moisture content has been achieved a maximum of 24 hours prior to the placement of concrete or moisture barriers. 3.10 Lateral Load Resistance Lateral loads may be resisted by soil friction and the passive resistance of the soil. The following parameters are recommended. • Passive Earth Pressure = 430 pcf (equivalent fluid weight). • Coefficient of Friction (soil to footing) = 0.41 • Retaining structures should be designed to resist the following lateral active earth pressures: Surface Slope of Retained Materials (Horizontal:Vertical) Equivalent Fluid Weight (pcf) Level 37 5:1 39 4:1 41 3:1 43 2:1 55 These active earth pressures are only applicable if the retained earth is allowed to strain sufficiently to achieve the active state. The required minimum horizontal strain to achieve the active state is approximately 0.0025H. Retaining structures should be designed to resist an at-rest lateral earth pressure if this horizontal strain cannot be achieved. • At-rest Lateral Earth Pressure = 60 pcf (equivalent fluid weight) Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page 10 The Mononobe-Okabe method is commonly utilized for calculating seismically induced active and passive lateral earth pressures and is based on the limit equilibrium Coulomb theory for static stress conditions. This method entails three fundamental assumptions (e.g., Seed and Whitman, 1970): Wall movement is sufficient to ensure either active or passive conditions, the driving soil wedge inducing the lateral earth pressures is formed by a planar failure surface starting at the heel of the wall and extending to the free surface of the backfill, and the driving soil wedge and the retaining structure act as rigid bodies, and therefore, experiences uniform accelerations throughout the respective bodies (U.S. Army Corps of Engineers, 2003, Engineering and Design - Stability Analysis of Concrete Structures). • Seismic Lateral Earth Pressure = 18 pcf (equivalent fluid weight). The seismic lateral earth pressure given above is a triangle increasing with depth, and the resultant of this pressure is an increment of force which should be applied to the back of the wall at 1/3 of the wall height from the wall base. The seismic increment of earth pressure should be added to the static active earth pressure. Even for the at-rest (Ko) condition, the seismic increment of earth pressure should be added to the static active earth pressure, not to the at-rest static earth pressure (SEAOC Seismology Committee 2019). Per 2019 CBC Section 1803.5.12 dynamic seismic lateral earth pressures shall be applied to foundation walls and retaining walls supporting more than 6 feet of backfill. Dynamic seismic lateral earth pressures may also be applied to shorter walls at the discretion of the structural engineer. 3.11 Drainage and Moisture Proofing Retaining structures should be drained to prevent the accumulation of subsurface water behind the walls. Backdrains should be installed behind all retaining walls exceeding 3 feet in height. A typical detail for retaining wall back drains is presented in Appendix C. All backdrains should be outlet to suitable drainage devices. Retaining wall less than 3 feet in height should be provided with backdrains or weep holes. Dampproofing and/or waterproofing should also be provided on all retaining walls exceeding 3 feet in height. Cal/OSHA construction safety orders should be observed during all underground work. 3.12 Plan Review Once a formal grading and foundation plans are prepared for the subject property, this office should review the plans from a geotechnical viewpoint, comment on changes from the plan used during preparation of this report and revise the recommendations of this report where necessary. 3.13 Geotechnical Observation and Testing The geotechnical engineer should be contacted to provide additional observation and testing during the following construction activities: • During the clearing and grubbing of the site. • During the demolition of any existing structures, buried utilities or other existing improvements. • During excavation and overexcavation of compressible soils. • During all phases of grading including ground preparation and filling operations. Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page 11 • During trenching and backfilling operations of buried improvements and utilities to verify proper backfill and compaction of the utility trenches. • After excavation and prior to placement of reinforcing steel or concrete within footing trenches to verify that footings are properly founded in competent materials. • During fine or precise grading involving the placement of any fills underlying driveways, sidewalks, walkways, or other miscellaneous concrete flatwork to verify proper placement, mixing and compaction of fills. • When any unusual conditions are encountered during construction. 4.00 CLOSURE The findings, conclusions and recommendations in this report were prepared in accordance with generally accepted engineering and geologic principles and practices. No other warranty, either expressed or implied, is made. This report has been prepared for City of Chula Vista to be used solely for design purposes. Anyone using this report for any other purpose must draw their own conclusions regarding required construction procedures and subsurface conditions. The geotechnical and geologic consultant should be retained during the earthwork and foundation phases of construction to monitor compliance with the design concepts and recommendations and to provide additional recommendations as needed. Should subsurface conditions be encountered during construction that are different from those described in this report, this office should be notified immediately so that our recommendations may be re-evaluated. FIGURES AND TABLES Max Field at Rienstra Park Retaining Wall and Slope Erosion City of Chula Vista RMA Job No.: 20-0287-01 Figure 1 SITE LOCATION MAP Base Map: Google Earth GEOTECHNICAL CONSULTANTS SITE Area with little or no vegetation REGIONAL GEOLOGIC MAP Scale: 1" ≈ 3,700' Source: Kennedy and Tan, 2008 SITE Max Field at Rienstra Park Retaining Wall and Slope Erosion City of Chula Vista RMA Job No.: 20-0287-01 Figure 2 Partial Legend Qyaa - Younger Alluvium Qop, - Old Paralic Deposits Qvop- Very Old Paralic Deposits Tsdss - San Diego Formation Sandstone Tsdcg- San Diego Formation Conglomerate REGIONAL FAULT MAP Scale: 1" ≈ 2 miles GEOTECHNICAL CONSULTANTS Orange - Holocene fault displacement Green - Late Quaternary fault displacement Purple - Quaternary fault Black - Pre-Quaternary fault Partial Legend Base Map: California Geological Survey Fault Activity Map of California, 2010 SITE Max Field at Rienstra Park Retaining Wall and Slope Erosion City of Chula Vista RMA Job No.: 20-0287-01 Figure 3 Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Figure 3 Photograph 1. Typical slope condition at west end of project. Photograph 2. Typical slope condition at east end of project, including portion of existing v-ditch with grass growing in concrete joints and cracks. Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Figure 3 Photograph 3. Area on east end of project with little or no vegetation exposing sandstone. Photograph 4. Area in center of project, just west of snack bar without vegetation and higher erosion. Exposes pebble conglomerate and sandstone at base of exposure. Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Figure 3 Photograph 5. V-ditch with grass growing cracks and joints in concrete. Grass growing on downslope side of v- ditch. Photograph 6. V-ditch with downslope erosion undermining v-ditch. Typically caused by surface runoff running over v-ditch and not being diverted to run down the v-ditch. Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Figure 3 Photograph 7. Cracks in v-ditch. Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Figure 3 Photograph 8. End of v-ditch with storm drain inlet. Also note build up of soil to left of v-ditch covered with dry grasses and the dry stacked blocks to restrain loose soil from slope. Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Figure 3 Photograph 9. Typical section of retaining wall, note soil and grass nearly overtopping wall and bushes growing near top of wall. Photograph 10. Base of wall with weep holes (open joints) that are nearly completely covered by pavement. Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Figure 3 Photograph 11. Wall east of snack bar. Area appears to have been previously modified. Soil at top of wall is being held back with boards or removed by hand. Wall appears to have been built too low and is bulging outward and footing is exposed (see Photograph 12). Photograph 12. Showing exposed footing at base of wall from Photograph 11. Footing only about 3-4” thick and bottom of footing is exposed with soil visible above asphalt pavement. Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Figure 3 Photograph 13. Section of wall just east of Photograph 11. No drain is visible behind wall. Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Figure 3 Photograph 14. Another area of wall modification that is bulging outward, located west of the press box. Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Figure 3 Photograph 15. Horizontal crack in wall with drain line exiting center of wall, area east of snack bar. Photograph 16. Damage to top course of wall, note loose soil at top of wall along with vertical cut into bedrock at top of photograph indicating that wall was not built high enough or upper courses of block were removed. Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Tables Maximum Slip Distance Distance Moment Rate Fault Zone & geometry (km)(mi.)Magnitude (mm/yr) Coronado Bank (rl-ss)24 15 7.4 3.0 Earthquake Valley (rl-ss)76 47 6.7 2.0 Elsinore - Temecula (rl-ss)86 53 7.8 5.0 Elsinore - Julian (rl-ss)71 44 6.8 5.0 Newport-Inglewood (rl-ss)71 44 6.9 1.5 Rose Canyon (rl-ss)14 9 6.9 1.5 Notes: Fault geometry - (ss) strike slip, (r) reverse, (n) normal, (rl) right lateral, (ll) left lateral, (o) oblique Fault and Seismic Data - California Geological Survey (Cao), 2003 and U.S. Geological National Seismic Hazards Maps online Sources Parameters NOTABLE FAULTS WITHIN 100 KILOMETERS AND SEISMIC DATA TABLE 1 Epicentral Distance Date Event Causitive Fault Magnitude (miles) Dec. 16, 1858 San Bernardino Area uncertain 6.0 96 Feb. 9,1890 San Jacinto uncertain 6.3 71 May 28, 1892 San Jacinto uncertain 6.3 67 Dec.25, 1899 San Jacinto San Jacinto 6.7 81 Sept. 20, 1907 San Bernardino Area uncertain 5.3 109 May 15, 1910 Elsinore Elsinore 6.0 76 April 21, 1918 Hemet San Jacinto 6.8 78 July 23, 1923 San Bernardino San Jacinto 6.0 96 March 11, 1933 Long Beach Newport-Inglewood 6.4 91 Dec. 4, 1948 Desert Hot Springs San Andreas or Banning 6.5 100 July 8, 1986 North Palm Springs Banning or Garnet Hills 5.6 99 July 13, 1986 Oceanside uncertain 5.4 51 June 28, 1992 Big Bear uncertain 6.5 108 Notes: Earthquake data: U.S. Geological Survey P.P. 1515 & online data, Southern California Earthqua California Geological Survey online data Magnitudes prior to 1932 are estimated from intensity. Magnitudes after 1932 are moment, local or surface wave magnitudes. Site Location: Site Longitude: -117.10047 Site Latitude: 32.6317 HISTORIC STRONG EARTHQUAKES IN SOUTHERN CALIFORNIA SINCE 1858 TABLE 2 APPENDIX B LABORATORY TESTS Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page A - 1 APPENDIX B LABORATORY TESTS B-1.00 LABORATORY TESTS B-1.01 Maximum Density Maximum density - optimum moisture relationships for the major soil types encountered during the field exploration were performed in the laboratory using the standard procedures of ASTM D1557. B-1.10 Direct Shear Direct shear tests were performed on representative samples of the major soil types encountered in the test holes using the standard test method of ASTM D3080 (consolidated and drained). Tests were performed on remolded samples. Remolded samples were tested at the insitu density and moisture of the sandstone and conglomerate. Shear tests were performed on a direct shear machine of the strain-controlled type. To simulate possible adverse field conditions, the samples were saturated prior to shearing. Several samples were sheared at varying normal loads and the results plotted to establish the angle of the internal friction and cohesion of the tested samples. B-1.14 Density of Split-Barrel Samples Soil samples were obtained by using a split-barrel sampler in accordance to standard method of ASTM D1586. B-1.16 Test Results Test results for all laboratory tests performed on the subject project are presented in this appendix. Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page A - 2 DENSITY - MOISTURE Sample Number Moisture (Percent) Density (lbs/ft3) Sandstone 9.1 113.5 Conglomerate 6.1 120.9 Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page A - 3 DIRECT SHEAR TEST ASTM D3080 Sample ID:Sandstone Maximum Dry Density (pcf) = 123.4 Optimum Moisture Content (%) = 11.3 Initial Dry Density (pcf) = 113.5 Initial Moisture Content (%) = 11.3 Final Moisture Content (%) = 20.0 Normal Peak Residual Pressure (psf)Shear Resist Shear Resist 1000 912 900 2000 1728 1704 4000 2892 2880 Peak Residual Cohesion (psf) =330 310 Friction Angle (deg) =33 33 Peak Residual 0 500 1000 1500 2000 2500 3000 0 500 1000 1500 2000 2500 3000 3500 4000 4500Shear Stress (psf)Normal Stress (psf) Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page A - 4 DIRECT SHEAR TEST ASTM D3080 Sample ID:Conglomerate Maximum Dry Density (pcf) = 127.3 Optimum Moisture Content (%) = 9.2 Initial Dry Density (pcf) = 120.9 Initial Moisture Content (%) = 9.2 Final Moisture Content (%) = 16.3 Normal Peak Residual Pressure (psf)Shear Resist Shear Resist 1000 1836 1800 2000 2184 2172 4000 3348 3336 Peak Residual Cohesion (psf) =1250 1220 Friction Angle (deg) =27 28 Peak Residual 0 500 1000 1500 2000 2500 3000 3500 4000 0 500 1000 1500 2000 2500 3000 3500 4000 4500Shear Stress (psf)Normal Stress (psf) APPENDIX B GENERAL EARTHWORK AND GRADING SPECIFICATIONS Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page B - 1 APPENDIX B GENERAL EARTHWORK AND GRADING SPECIFICATIONS B-1.00 GENERAL DESCRIPTION B-1.01 Introduction These specifications present our general recommendations for earthwork and grading as shown on the approved grading plans for the subject project. These specifications shall cover all clearing and grubbing, removal of existing structures, preparation of land to be filled, filling of the land, spreading, compaction and control of the fill, and all subsidiary work necessary to complete the grading of the filled areas to conform with the lines, grades and slopes as shown on the approved plans. The recommendations contained in the geotechnical report of which these general specifications are a part of shall supersede the provisions contained hereinafter in case of conflict. B-1.02 Laboratory Standard and Field Test Methods The laboratory standard used to establish the maximum density and optimum moisture shall be ASTM D1557. The insitu density of earth materials (field compaction tests) shall be determined by the sand cone method (ASTM D1556), direct transmission nuclear method (ASTM D6938) or other test methods as considered appropriate by the geotechnical consultant. Relative compaction is defined, for purposes of these specifications, as the ratio of the in-place density to the maximum density as determined in the previously mentioned laboratory standard. B-2.00 CLEARING B-2.01 Surface Clearing All structures marked for removal, timber, logs, trees, brush and other rubbish shall be removed and disposed of off the site. Any trees to be removed shall be pulled in such a manner so as to remove as much of the root system as possible. B-2.02 Subsurface Removals A thorough search should be made for possible underground storage tanks and/or septic tanks and cesspools. If found, tanks should be removed and cesspools pumped dry. Any concrete irrigation lines shall be crushed in place and all metal underground lines shall be removed from the site. B-2.03 Backfill of Cavities All cavities created or exposed during clearing and grubbing operations or by previous use of the site shall be cleared Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page B - 2 of deleterious material and backfilled with native soils or other materials approved by the soil engineer. Said backfill shall be compacted to a minimum of 90% relative compaction. B-3.00 ORIGINAL GROUND PREPARATION B-3.01 Stripping of Vegetation After the site has been properly cleared, all vegetation and topsoil containing the root systems of former vegetation shall be stripped from areas to be graded. Materials removed in this stripping process may be used as fill in areas designated by the soil engineer, provided the vegetation is mixed with a sufficient amount of soil to assure that no appreciable settlement or other detriment will occur due to decaying of the organic matter. Soil materials containing more than 3% organics shall not be used as structural fill. B-3.02 Removals of Non-Engineered Fills Any non-engineered fills encountered during grading shall be completely removed and the underlying ground shall be prepared in accordance to the recommendations for original ground preparation contained in this section. After cleansing of any organic matter the fill material may be used for engineered fill. B-3.03 Overexcavation of Fill Areas The existing ground in all areas determined to be satisfactory for the support of fills shall be scarified to a minimum depth of 6 inches. Scarification shall continue until the soils are broken down and free from lumps or clods and until the scarified zone is uniform. The moisture content of the scarified zone shall be adjusted to within 2% of optimum moisture. The scarified zone shall then be uniformly compacted to 90% relative compaction. Where fill material is to be placed on ground with slopes steeper than 5:1 (H:V) the sloping ground shall be benched. The lowermost bench shall be a minimum of 15 feet wide, shall be a minimum of 2 feet deep, and shall expose firm material as determined by the geotechnical consultant. Other benches shall be excavated to firm material as determined by the geotechnical consultant and shall have a minimum width of 4 feet. Existing ground that is determined to be unsatisfactory for the support of fills shall be overexcavated in accordance to the recommendations contained in the geotechnical report of which these general specifications are a part. B-4.00 FILL MATERIALS B-4.01 General Materials for the fill shall be free from vegetable matter and other deleterious substances, shall not contain rocks or lumps of a greater dimension than is recommended by the geotechnical consultant, and shall be approved by the geotechnical consultant. Soils of poor gradation, expansion, or strength properties shall be placed in areas designated by the geotechnical consultant or shall be mixed with other soils providing satisfactory fill material. B-4.02 Oversize Material Oversize material, rock or other irreducible material with a maximum dimension greater than 12 inches, shall not be placed in fills, unless the location, materials, and disposal methods are specifically approved by the geotechnical Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page B - 3 consultant. Oversize material shall be placed in such a manner that nesting of oversize material does not occur and in such a manner that the oversize material is completely surrounded by fill material compacted to a minimum of 90% relative compaction. Oversize material shall not be placed within 10 feet of finished grade without the approval of the geotechnical consultant. B-4.03 Import Material imported to the site shall conform to the requirements of Section 4.01 of these specifications. Potential import material shall be approved by the geotechnical consultant prior to importation to the subject site. B-5.00 PLACING AND SPREADING OF FILL B-5.01 Fill Lifts The selected fill material shall be placed in nearly horizontal layers which when compacted will not exceed approximately 6 inches in thickness. Thicker lifts may be placed if testing indicates the compaction procedures are such that the required compaction is being achieved and the geotechnical consultant approves their use. Each layer shall be spread evenly and shall be thoroughly blade mixed during the spreading to insure uniformity of material in each layer. B-5.02 Fill Moisture When the moisture content of the fill material is below that recommended by the soils engineer, water shall then be added until he moisture content is as specified to assure thorough bonding during the compacting process. When the moisture content of the fill material is above that recommended by the soils engineer, the fill material shall be aerated by blading or other satisfactory methods until the moisture content is as specified. B-5.03 Fill Compaction After each layer has been placed, mixed, and spread evenly, it shall be thoroughly compacted to not less than 90% relative compaction. Compaction shall be by sheepsfoot rollers, multiple-wheel pneumatic tired rollers, or other types approved by the soil engineer. Rolling shall be accomplished while the fill material is at the specified moisture content. Rolling of each layer shall be continuous over its entire area and the roller shall make sufficient trips to insure that the desired density has been obtained. B-5.04 Fill Slopes Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equipment. Compacting of the slopes may be done progressively in increments of 3 to 4 feet in fill height. At the completion of grading, the slope face shall be compacted to a minimum of 90% relative compaction. This may require track rolling or rolling with a grid roller attached to a tractor mounted side-boom. Slopes may be over filled and cut back in such a manner that the exposed slope faces are compacted to a minimum of 90% relative compaction. Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page B - 4 The fill operation shall be continued in six inch (6") compacted layers, or as specified above, until the fill has been brought to the finished slopes and grades as shown on the accepted plans. B-5.05 Compaction Testing Field density tests shall be made by the geotechnical consultant of the compaction of each layer of fill. Density tests shall be made at locations selected by the geotechnical consultant. Frequency of field density tests shall be not less than one test for each 2.0 feet of fill height and at least every one thousand cubic yards of fill. Where fill slopes exceed four feet in height their finished faces shall be tested at a frequency of one test for each 1000 square feet of slope face. Where sheepsfoot rollers are used, the soil may be disturbed to a depth of several inches. Density reading shall be taken in the compacted material below the disturbed surface. When these readings indicate that the density of any layer of fill or portion thereof is below the required density, the particular layer or portion shall be reworked until the required density has been obtained. B-6.00 SUBDRAINS B-6.01 Subdrain Material Subdrains shall be constructed of a minimum 4-inch diameter pipe encased in a suitable filter material. The subdrain pipe shall be Schedule 40 Acrylonitrile Butadiene Styrene (ABS) or Schedule 40 Polyvinyl Chloride Plastic (PVC) pipe or approved equivalent. Subdrain pipe shall be installed with perforations down. Filter material shall consist of 3/4" to 1 1/2" clean gravel wrapped in an envelope of filter fabric consisting of Mirafi 140N or approved equivalent. B-6.02 Subdrain Installation Subdrain systems, if required, shall be installed in approved ground to conform the approximate alignment and details shown on the plans or herein. The subdrain locations shall not be changed or modified without the approval of the geotechnical consultant. The geotechnical consultant may recommend and direct changes in the subdrain line, grade or material upon approval by the design civil engineer and the appropriate governmental agencies. B-7.00 EXCAVATIONS B-7.01 General Excavations and cut slopes shall be examined by the geotechnical consultant. If determined necessary by the geotechnical consultant, further excavation or overexcavation and refilling of overexcavated areas shall be performed, and/or remedial grading of cut slopes shall be performed. B-7.02 Fill-Over-Cut Slopes Where fill-over-cut slopes are to be graded the cut portion of the slope shall be made and approved by the geotechnical consultant prior to placement of materials for construction of the fill portion of the slope. Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page B - 5 B-8.00 TRENCH BACKFILL B-.01 General Trench backfill within street right of ways shall be compacted to 90% relative compaction as determined by the ASTM D1557 test method. Backfill may be jetted as a means of initial compaction; however, mechanical compaction will be required to obtain the required percentage of relative compaction. If trenches are jetted, there must be a suitable delay for drainage of excess water before mechanical compaction is applied. B-9.00 SEASONAL LIMITS B-9.01 General No fill material shall be placed, spread or rolled while it is frozen or thawing or during unfavorable weather conditions. When the work is interrupted by heavy rain, fill operations shall not be resumed until field tests by the soils engineer indicate that the moisture content and density of the fill are as previously specified. B-10.00 SUPERVISION B-10.01 Prior to Grading The site shall be observed by the geotechnical consultant upon completion of clearing and grubbing, prior to the preparation of any original ground for preparation of fill. The supervisor of the grading contractor and the field representative of the geotechnical consultant shall have a meeting and discuss the geotechnical aspects of the earthwork prior to commencement of grading. C-10.02 During Grading Site preparation of all areas to receive fill shall be tested and approved by the geotechnical consultant prior to the placement of any fill. The geotechnical consultant or his representative shall observe the fill and compaction operations so that he can provide an opinion regarding the conformance of the work to the recommendations contained in this report. Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page B - 6 RETAINING WALL DRAINAGE DETAIL Soil backfill, compacted to 90% relative compaction* Filter fabric envelope (Mirafi 140N or approved equivalent) ** Minimum of 1 cubic foot 3" diameter perforated PVC pipe (schedule 40 or equivalent) with perforations oriented down as depicted minimum 1% gradient to suitable outlet. 3" min. Wall footing Compacted fill Finished Grade Retaining wall Wall waterproofing per architect's specifications * Based on ASTM D1557 ** If class 2 permeable material (See gradation to left) is used in place of 3/4" - 1 1/2" gravel. Filter fabric may be deleted. Class 2 permeable material compacted to 90% relative compaction. * SPECIFICATIONS FOR CLASS 2 PERMEABLE MATERIAL (CAL TRANS SPECIFICATIONS) Sieve Size % Passing 1" 3/4" 3/8" No.4 No.8 No.30 No.50 No.200 0-3 0-7 5-15 18-33 25-40 40-100 90-100 100 per linear foot of 3/4" crushed rock 50 feet on center to a joints or outlet drain at Provide open cell head suitable drainage device . .. . . . . .. . . . . APPENDIX D REFERENCES Max Field at Rienstra Park Slope Erosion and Retaining Wall June 19, 2020 City of Chula Vista RMA Job No.: 20-0287-01 Page C - 1 APPENDIX C REFERENCES 1. Bryant, W.A. and Hart, E.W., 2007, Fault-Rupture Hazard Zones in California: California Department of Conservation, Division of Mines and Geology Special Publication 42, Interim Revision 2007 and online updates. 2. California Building Standards Commission, 2019 California Building Code. 3. California Department of Conservation, Division of Mines and Geology, 2008, Guidelines for Evaluating and Mitigating Seismic Hazards in California, Special Publication 117. 4. Green Book, 2018, Standard Specifications for Public Works Construction (SPPWC). 5. Google Earth, Aerial Photographs, 2016, 2014, 2013, 2012, 2011, 2009, 2006, 2005, 2003, 2002, 1996. 6. Historicaerials.com, Aerial Photographs, 2012, 2010, 2009, 2005, 2002, 1996, 1978, 1972, 1967, 1966. 7. Jennings, C.W., 1994, An Explanatory Text to Accompany the Fault Activity Map of California and Adjacent Areas: California Division of Mines and Geology Map No. 6. 8. Jennings, C.W., and Bryant, W.A, 2010, Fault Activity Map of California, California Geological Survey, Geologic Data Map No. 6. 9. Kennedy, M.P. and Tan, S.S., 2008, Geologic Map of the San Diego 30’ x 60’ Quadrangle, California: California Geological Survey Map No. 3. 10. Martin, G.R. and Lew, M., 1999, Recommended Procedures for Implementation of DMG Special Publication 117, Guidelines for Analyzing and Mitigating Liquefaction Hazards in California, Southern California Earthquake Center publication. 11. SEAOC Seismology Committee, 2019, “Seismically Induced Lateral Earth Pressures on Retaining Structures and Basement Walls,” August 2019, The SEAOC Blue Book: Seismic Design Recommendations, Structural Engineers Association of California, Sacramento, CA. 12. Seed, H.B. and Whitman, R.V., 1970, Design of Earth Structures for Dynamic Loads in American Society of Civil Engineers Specialty Conference State-of-the Art Paper, Lateral Stresses in the Ground and Design of Earth- Retaining Structures. 13. Tokimatsu, K. and Seed, H.B., 1987, Evaluation of Settlements in Sands Due to Earthquake Shaking, Journal of Soil Mechanics and Foundation Engineering, Vol. 113, No. 8. 14. Youd, T.L. et al. (2001). "Liquefaction resistance of soils, summary report from the 1996 NCEER and 1998 NCEER/NSF workshops on evaluation of liquefaction resistance of soils, Journal of Geotechnical and GeoEnvironmental Engineering, ASCE (127) 4, pp. 297-131. 11883 1 May 2020 MEMORANDUM To: Mr. Frank Rivera, City of Chula Vista From: Patricia Schuyler, Dudek Subject: Biological Review of the Max Field Project Site Date: May 20, 2020 cc: Sean Kilkenny, Dudek Attachment(s): Figure 1, Biological Resources Dudek biologists reviewed the project site for biological constraints pertaining to the redevelopment of Max Field (Reinstra Park) located in the City of Chula Vista. The purpose of this memo is to provide an analysis of potential biological constraints within the site that would affect permitting, scheduling and cost for the re-development of the property. The potential biological resource impacts have been evaluated without a preliminary design. Design adjustments may be necessary to minimize impacts to regulated resources in order to reduce costs and expedite the development process. 1 Location and Surrounding Uses The project site is located along Max Avenue within the City of Chula Vista. Approximate center coordinates of the site are 32.602932, -117.047155. The Loma Verde Aquatic Center and elementary school are located to the west of the project site. Residential development surrounds the project site. A San Diego Gas & Electric (SDG&E) easement abuts the project site to the north and is the only open space within the vicinity of the project site. 2 Existing Conditions and Constraints A site visit was conducted in July 2019 by Dudek biologists Patricia Schuyler and Katie Dayton. The project site was evaluated for general vegetation communities and the potential to support special-status wildlife and plant species. During the site visit, Dudek biologists utilized a GPS unit to map the boundaries of an existing channel; (see Figure 1) however, a formal jurisdictional delineation for the site was not conducted. Focused surveys for rare plants or sensitive wildlife species were not conducted. The project site is largely comprised of developed land (parking lot, baseball fields and facilities) and associated landscaping. Non-native grassland with a small pocket of maritime succulent scrub occurs in the northwestern portion of the project site. Scattered non-native trees are located along the western edge of the site. The general location of these vegetation communities are shown on Figure 1. It should be noted that detailed vegetation mapping was not conducted for the project site, only general locations and habitat types were recorded. There may be pockets of disturbed habitat located within the non-native grassland. APPENDIX D Memorandum Subject: Biological Review of the Max Field Project Site 11883 2 May 2020 The SDG&E easement located north of the project site may provide for local wildlife movement but it is expected that only urbanized wildlife such as coyotes and raccoons would utilize this area due to the intensity of the surrounding development. 3 Biological Constraints As previously stated, the project site is largely development. If redevelopment of the site is confined to developed areas, no impacts to biological resources would occur. There is a channel immediately adjacent to the project site. Any impacts to this feature would require permits from the Regulatory Agencies (i.e. U.S. Army Corps of Engineers (USACE), Regional Water Quality Control Board (RWQCB) and California Department of Fish and Wildlife (CDFW) (discussed in Section 4). Bridging the channel, as long as the abutments are located outside of the limits of the channel, should not require permits from the Regulatory Agencies or associated mitigation. However, Dudek recommends attending a pre-application meeting with the Resource Agency to present the project and confirm that permit applications would not be required. The City and the Resource Agencies do not require a specific buffer between development and stream channels or wetlands. The existing channel is located immediately adjacent to development, with a minimal buffer. It is recommended that re-development activities stay within the existing development footprint. In addition, a formal delineation can be conducted for the project site to clearly define the limits of the stream channel should it be needed. Any impacts to non-native grassland and maritime succulent scrub would require mitigation per the Chula Vista Subarea Plan. Mitigation for non-native grasslands would range from 0.5:1 to 1:1 (impact to mitigation) depending on the location of the mitigation. Mitigation for maritime succulent scrub ranges from 1:1 to 2:1. Should the re- development consider providing a more permanent walking path from the school to the project site, it is recommended that a biologist review the path location to determine that it is located within the least sensitive portion of the project site. 4 General Information on Wetland Permits Impacts to certain habitat types that are considered to be jurisdictional aquatic resources (i.e., wetlands/riparian habitat, waters/streambed), will require permits from the following jurisdictions: the (USACE) pursuant to Section 404 of the federal Clean Water Act; the RWQCB pursuant to Section 401 of the federal Clean Water Act; and the CDFW pursuant to Section 1602 of the California Fish and Game Code. These permits would be required for impacts to the channel located along the western edge of the project site. USACE Permitting Requirements. The actual extent of USACE regulated resources within the project site will be ultimately determined by the USACE and how they apply the new Navigable Waters Protection Rule. This discussion assumes that the USACE will assert jurisdiction over the stream channel. Nationwide Permits (NWPs) are issued for a variety of projects with minimal impacts (typically less than 0.5 acre and 300 linear feet) to waters of the U.S., including wetlands. The NWP Program requires the submittal of a Pre- Construction Notification (PCN) to the USACE. The PCN needs to include a project description, a purpose and need statement for the project, a description of efforts to avoid and minimize impacts to jurisdictional areas, and a conceptual mitigation and monitoring plan to compensate for proposed impacts. Additional environmental review under the National Environmental Policy Act (NEPA) is not required for a NWP. As a result, once the USACE has Memorandum Subject: Biological Review of the Max Field Project Site 11883 3 May 2020 determined that the application is complete and the project meets the requirements of the NWP, authorization to use the NWP can be issued. It has been our experience that the USACE can take anywhere from three to six months to even a year to issue a NWP. Typical reasons for delay involve interpretations of the NWP conditions, additional requirements to avoid and minimize impacts to jurisdictional areas, circulation of the PCN to the U.S. Fish and Wildlife Service (USFWS), and if appropriate and necessary, the U.S. Environmental Protection Agency (EPA), responding to the USFWS and EPA comments and finalizing the conceptual mitigation and monitoring plan. In addition, it should be noted that the USACE will not typically authorize the use of NWPs until the California Environmental Quality Act (CEQA) document for the project is certified by the lead agency and the RWQCB has issued a Water Quality Certificate in accordance with Section 401 of the federal Clean Water Act. Applications could be submitted to the USACE prior to certification or adoption of the CEQA document. However, the schedule for beginning construction should acknowledge the six month-to-one year processing time for the NWP and that a NWP cannot be issued until the CEQA document is certified/adopted. Another source of delay with the NWP process can be conforming to review requirements of the State Historic Preservation Officer (SHPO) for cultural resources. Review and acceptance by SHPO will be critical for processing the Nationwide Permit, should any cultural resources occur on site. Please note that should impacts to jurisdictional waters of the U.S., including wetlands, exceed 0.5 acre or 300 linear feet, a Section 404 Individual Permit from the USACE may be required in lieu of a Nationwide Permit. An Individual Permit requires NEPA compliance (that is, preparation of an Environmental Assessment), preparation of a Section 404(b)(1) Alternatives Analysis and may take well over a year to eighteen months complete. The USACE may waive the linear restriction depending on a number of factors including the quality of the waters and the length that the impacts exceed the 300 foot limitation. CDFW Permitting Requirements. Pursuant to Section 1602 of the California Fish and Game Code, a Streambed Alteration Agreement will be needed from the CDFW prior to impacts to streambed and/or associated riparian habitat. An application is submitted to the CDFW Lake and Streambed Alteration Program which contains the following information: a detailed project description; a statement of purpose and need; an impacts analysis; a discussion of avoidance and minimization of impacts; evidence of a jurisdictional delineation; a draft conceptual mitigation and monitoring plan; all associated figures (vicinity maps, project site map, construction/grading cross- sections, mitigation area, etc.) and copies of the permit applications submitted to the RWQCB and USACE. Once the notification package has been submitted to the CDFW, the CDFW has 30 calendar days to determine if the notification package submitted is complete. Once the package has been deemed complete, the CDFW has 60 days to issue a draft agreement. Therefore, the total timing needed to obtain a Section 1602 Streambed Alteration Agreement is 90 days. Additional processing time may be needed by the CDFW to review and approve all revegetation efforts prior to issuing the Agreement. Similar to the USACE, the CDFW will not issue the Section 1602 Streambed Alteration Agreement until the CEQA document for the project is certified. Our experience with CDFW in obtaining 1602 Agreements is that although the timing is set at 90 days, rarely is the Agreement received in that time period. Assuming receipt of the Section 1602 Agreement in six months is probably more realistic. RWQCB Permitting Requirements. A Water Quality Certification is required from the RWQCB in accordance with Section 401 of the federal Clean Water Act prior to impacts to jurisdictional areas. The RWQCB must certify that the Memorandum Subject: Biological Review of the Max Field Project Site 11883 4 May 2020 project will not adversely impact the water quality downstream. Typically the RWQCB evaluates the type of facilities proposed at drainage outlets such as rip-rap dissipaters necessary to control the velocity of runoff from the project, as well as other Best Management Practices (BMPs) such as grassy swales for storm water treatment. An application is submitted with much of the same information as required for the USACE PCN and CDFW, but requires additional information regarding impacts to beneficial uses of the impacted watershed in accordance with the Region 9 Basin Plan, impacts to wildlife corridors, information regarding the character of the impacted stream channel upstream and downstream, and cumulative impacts within the watershed. The RWQCB has 30 days following receipt of an application to notify the applicant regarding completeness of the submitted material. Once an application has been deemed complete, the RWQCB has anywhere from 60 days to one year to either issue the permit or deny the project. During this time, the RWQCB can request additional materials to better clarify project impacts, pre- and post-construction water quality treatment, mitigation, or other aspects of the project. Assuming completeness at the time of submittal, the timing for obtaining a 401 certification is approximately 90 days. Similar to the USACE and CDFW, the RWQCB will not issue the Section 401 Water Quality Certificate until the CEQA document for the project is certified. Attachment A Figure 1 – Biological Resources Date: 8/1/2019 - Last saved by: ckubacki - Path: Z:\Projects\j1188301\MAPDOC\WORKING\Figure1_Channel_Limits_Vegetation_11x17.mxdSOURCE: SANGIS 2017 0 10050Feetn DEV, Developed MSS, Maritime Succulent Scrub NNG, Non-Native Grassland NNW, Non-Native Woodland FIGURE 1 Vegetation "J 2 6x5 ft culvert Channel Limits Project Site Max Field Reinstra Park Biological Resources