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HomeMy WebLinkAboutAPPX-G_V8-Water-Cons_11-00-10Water Conservation Plan Appendix G i TABLE OF CONTENTS PAGE NO. II-8.1 EXECUTIVE SUMMARY ........................................................................................ 1 II-8.2 INTRODUCTION ..................................................................................................... 1 II-8.3 PURPOSE................................................................................................................. 3 II-8.4 PROJECT DESCRIPTION ...................................................................................... 4 II-8.5 WATER SERVICE AND SUPPLY ........................................................................... 8 II-8.6 PROJECTED WATER USE ..................................................................................... 8 II-8.6a Potable Water Demand ............................................................... 8 II-8.6b Recycled Water Demand ............................................................. 9 II-8.7 MANDATED WATER CONSERVATION MEASURES ....................................... 11 II-8.8 LOCAL WATER CONSERVATION REQUIREMENTS ....................................... 11 Residential Measures-Mandatory ............................................................. 12 Non-Residential Measures-Mandatory ..................................................... 12 Non-Mandatory Measures ........................................................................ 12 II-8.9 WATER CONSERVATION ESTIMATED SAVINGS ........................................... 13 Water Conservation Summary ................................................................. 15 II-8.10 IMPLEMENTATION MEASURES ....................................................................... 16 II-8.11 MONITORING ...................................................................................................... 16 REFERENCES ii LIST OF TABLES PAGE TABLE 1 SITE UTILIZATION SUMMARY TABLE ......................................................... 6 TABLE 2 PROJECTED POTABLE WATER DEMANDS FOR OTAY RANCH VILLAGE 8 WEST .................................................................... 8 TABLE 3 PROJECTED RECYCLED WATER DEMANDS FOR OTAY RANCH VILLAGE 8 WEST .................................................................... 9 TABLE 4 MANDATED WATER CONSERVATION DEVICES ...................................... 11 TABLE 5 VILLAGE 8 WEST MULTI-FAMILY PROPOSED WATER CONSERVATION MEASURES ....................................................................... 14 TABLE 6 VILLAGE 8 WEST SINGLE FAMILY RESIDENTIAL WATER CONSERVATION MEASURES ....................................................................... 14 TABLE 7 VILLAGE 8 WEST WATER CONSERVATION SUMMARY .......................... 15 TABLE 8 VILLAGE 8 WEST IMPLEMENTATION AND MONITORING PROGRAM .................................................................... 16 iii LIST OF FIGURES PAGE FIGURE 1 PROPOSED LAND USE PLAN ......................................................................... 5 FIGURE 2 POTENTIAL RECYCLED WATER USE AREAS ........................................... 10 iv ABBREVIATIONS ac - acre ac-ft - acre-foot cfd - community facilities district cfs - cubic feet per second gpd - gallons per day gpf - gallons per flush gpm - gallons per minute HOA - homeowner’s association mgd - million gallons per day USEFUL CONVERSIONS 1 acre-foot = 325,829 gallons 1 mgd = 1,000,000 gallons/day 1 cfs = 448.8 gpm 1 cubic foot = 7.48 gallons 1 mgd = 694.4 gpm DEXTER WILSON ENGINEERING, INC. PAGE 1 II-8.1 EXECUTIVE SUMMARY The City of Chula Vista’s Growth Management Ordinance (CVMC 19.09.050C) requires that all development projects with 50 dwelling units or greater prepare a Water Conservation Plan at the time of the Sectional Planning Area plan preparation. This plan presents a review of presently available technologies and practices which result in water conservation in primarily residential development. This report presents water conservation measures that will be incorporated into the planning and design of Otay Ranch Village 8 West, including the requirements outlined in the Landscape Water Conservation Ordinance. Village 8 West includes portions of Otay Ranch Villages 4, 7, and 8. Proposed development within Village 8 West includes 2,050 mixed density residential dwelling units, schools, commercial, parks, and opens space. The residential development proposes 621 single family residential units and 1,429 multi-family and mixed use units. The Otay Water District is the local water agency that will supply potable water and recycled water to Village 8 West. The total estimated average potable and recycled water use for the project is 0.79 mgd and 0.14 mgd, respectively. The State and local government have mandated a number of water conservation measures. The focus of this study is on the implementation of non-mandated water conservation measures. The project will install hot water pipe insulation, pressure reducing valves, and water efficient dishwashers in all single family and multi-family residential units. Additionally, the developer will install dual flush toilets and water efficient landscaping in compliance with the Landscape Water Conservation Ordinance. At buildout of the project, implementation of the above measures along with the use of recycled water would reduce estimated potable water usage on the project by an estimated 202,505 gpd. II-8.2 INTRODUCTION In recent years, the subject of water conservation has been given increased attention. The growing awareness of the need and value of water conservation has been sparked by local and regional water purveyors concerned about meeting the future water demands of their customers, particularly during drought conditions. Water conservation provides an alternative approach to the problem of finding new water sources to meet the water demand for a proposed community. The intent of water conservation is to manage water demand so that the customers receive adequate service but use less water. DEXTER WILSON ENGINEERING, INC. PAGE 2 Much has been done to educate consumers about limitations of water supply, the serious implications of a long-term drought and the need for water conservation, but there is a practical limit to the percentage reduction of water use in established communities. This limit is a result of the types of plumbing fixtures installed in existing homes as well as the difficulty in altering consumers' established patterns of water use. Any water conservation effort, voluntary or mandatory, requires the cooperation of the public. Public information should be utilized to inform and convince the consumer that a change in personal water use habits is in everyone's best interest. In recent years, the private development sector has become more attuned to the concerns of water availability and has recognized the value of addressing water conservation issues throughout planned development projects. By incorporating low water use plumbing fixtures, promoting drought tolerant landscaping, and providing educational materials to homeowners within the development project, private developments can do much to cultivate an interest in water conservation and establish new patterns of water use. These efforts can have significant impacts with regard to reducing the need for securing and importing larger quantities of water for use in San Diego County. The Landscaping Water Conservation Ordinance went into effect on January 1, 2010 and will require homeowners to be efficient with the landscape systems and plant selection. In 2006 the State repealed the Water Conservation in Landscaping Act and adopted a new Water Conservation in Landscaping Act, Government Code Sections 65591 et seq. The new Act requires the Department of Water Resources to update the previously adopted model efficient landscape ordinance that provides for greater efforts at water conservation and more efficient use of water in landscaping. Government Code Section 65595 requires that on or before January 1, 2010 a local agency shall adopt a water efficient landscape ordinance that is at least as effective in conserving water as the updated model ordinance or adopt the model ordinance. If a local agency does not adopt a water efficient landscape ordinance by the deadline, the updated model ordinance shall apply within the local agency’s jurisdiction and shall be enforced by the local agency. The City of Chula Vista City Council adopted an ordinance that complies with the findings and declarations of the State’s Water Conservation in Landscaping Act and is as effective as the State’s updated model water efficient landscape ordinance. This water conservation plan incorporates the requirement of the City’s ordinance. DEXTER WILSON ENGINEERING, INC. PAGE 3 The Otay Ranch Village 8 West project is within the Otay Ranch General Development Plan (GDP). The Otay Ranch GDP was adopted in 1993 and included objectives for water conservation to be incorporated into the development of Otay Ranch. These objectives included the implementation of water efficient fixtures, increased use of drought tolerant landscaping, and use of recycled water for irrigation. The objective of these measures is to reduce the per capita water use within Otay Ranch by 25 percent as compared to county wide 1989 per capita levels. This report will demonstrate how the City, in partnership with the Otay Water District and development community are meeting these objectives. II-8.3 PURPOSE The State Legislature determined in the Water Conservation in Landscaping Act that the State’s water resources are in limited supply. The Legislature also recognized that while landscaping is essential to the quality of life in California, landscape design and maintenance must be water efficient. The City of Chula Vista’s Growth Management Ordinance requires that all major development projects (50 dwelling units or greater) prepare a Water Conservation Plan at the time of Sectional Planning Area Plan preparation. Consistent with the Master Planned Communities Outline, Section II-8 of the Village 8 West SPA Plan contains the Water Conservation Plan. The City has adopted guidelines for the preparation and implementation of required water conservation plans. This report will present water conservation measures which will be incorporated into the planning and design of the project, including an estimate of the anticipated water savings. Approximately half of the water used by residences in California is used outdoors. For this reason, the City’s Landscape Water Conservation Ordinance will be an important component of reduced water usage. Although not covered in detail, there are several secondary benefits to conserving water that should be kept in mind when reviewing material in this report. These benefits include reduced sewage flows, reduced natural gas use, and reduced electricity use. Using less water in the shower, for example, reduces the amount of water input into the sewer system and reduces the amount of energy required to heat the water. DEXTER WILSON ENGINEERING, INC. PAGE 4 II - 8.4 PROJECT DESCRIPTION Proposed development within the Village 8 West boundary includes 2,050 mixed density residential dwelling units, schools, retail commercial, parks, and opens space. The residential development proposes 621 single family residential units and 1,429 multi-family units. Figure 1 provides the proposed land use plan for the project and Table 1 provides a land use summary. DEXTER WILSON ENGINEERING, INC. PAGE 6 TABLE 1 SITE UTILIZATION SUMMARY TABLE Planning Area Gross Acres Maximum Residential Units Maximum Commercial Square Footage Mixed Use B 1.4 25 0 C 6.9 130 36,000 F 5.4 103 25,000 H-1 7.7 33 144,000 H-2 1.2 0 12,000 J 5.4 160 18,000 L 14.2 448 65,000 Subtotal 42.2 899 300,000 Multi-Family Residential E 5.3 95 --- I 6.8 122 --- M 8.5 153 --- O 8.9 160 --- Subtotal 29.5 530 --- Single Family Residential Q 14.6 160 --- U 11.9 130 --- N 24.1 117 --- P 38.1 124 --- V 25.3 90 --- Subtotal 114 621 --- Community Purpose Facility R 5.8 --- --- Schools D 21.0 --- --- S 11.4 --- --- Subtotal 32.4 --- --- DEXTER WILSON ENGINEERING, INC. PAGE 7 TABLE 1 SITE UTILIZATION SUMMARY TABLE Planning Area Gross Acres Maximum Residential Units Maximum Commercial Square Footage Parks A 17.4 --- --- G 3.1 --- --- T 7.5 --- --- Subtotal 28.0 --- --- Open Space Y 15.6 --- --- X 3.5 --- --- Subtotal 19.1 --- --- Other W 19.6 --- --- R-O-W 29.5 --- --- Subtotal 49.1 --- --- TOTAL 320.1 2,050 300,000 DEXTER WILSON ENGINEERING, INC. PAGE 8 II-8.5 WATER SERVICE AND SUPPLY The Otay Water District is the local water agency that will supply potable water and recycled water to Village 8 West. The Otay Water District relies solely on the San Diego County Water Authority (SDCWA) for its potable water supply. The SDCWA is the largest of 27 member agencies of the Metropolitan Water District of Southern California (MWD), which is the primary importer of domestic water in Southern California. II-8.6 PROJECTED WATER USE II-8.6a Potable Water Demand Water use is affected by, among other things, climate and the type of development. In California, recent trends towards the construction of more multi-unit housing, the general reduction in residential lot size, and a number of local agency water conservation programs in effect are all tending to reduce per capita water consumption. Potable water demands were projected by taking the total development for each land use and multiplying by water use factors. Table 2 provides the projected potable water demand for Village 8 West. The total estimated potable water use is 0.79 mgd. The estimated potable water usage in Table 2 is reduced by the use of recycled water for irrigation of open space slopes, parks, common areas, etc. Potable water use factors were taken from the October 2008 Otay Water District Water Resources Master Plan. TABLE 2 PROJECTED POTABLE WATER DEMANDS FOR OTAY RANCH VILLAGE 8 WEST Land Use Quantity Unit Demand Average Day Demands, gpd Single-Family Residential 621 units 500 gpd/unit 310,500 Multiple-Family Residential 1,429 units 255 gpd/unit 364,395 Commercial – Retail 300,000 SF 0.14 gpd/SF 42,000 Schools 32.4 ac 1,428 gpd/ac 46,270 CPF 5.8 ac 714 gpd/ac 4,140 Parks – Potable --- ---19,270 1 TOTAL 786,575 1Parks are to be irrigated with recycled water, but the parks have potable water uses also per the water study for Village 8 West. DEXTER WILSON ENGINEERING, INC. PAGE 9 II-8.6b Recycled Water Demand In accordance with Section 26 of the Otay Water District Code of Ordinances, Village 8 West will utilize recycled water for the irrigation of open space slopes, parks, parkway and median landscaping, and the common areas of schools, commercial, and multi-family residential sites. Figure 2 identifies the potential recycled water use areas and Table 3 provides the estimated recycled water demand. The total estimated recycled water demand is 0.14 mgd. TABLE 3 PROJECTED RECYCLED WATER DEMANDS FOR OTAY RANCH VILLAGE 8 WEST Land Use Area, Acres Percentage to be Irrigated Irrigated Acreage Recycled Water Irrigation Factor, gpd/ac Average Recycled Water Demand, gpd Open Space, Slopes, Parkways 20 100 1 20.0 2,155 43,100 Parks 28.0 100 28.0 2,155 60,340 Schools 32.4 20 6.5 2,155 14,010 CPF 5.8 10 0.6 2,155 1,290 Mixed Use 42.2 10 4.2 2,155 9,050 Multi-family 29.5 15 4.4 2,155 9,480 TOTAL 137,270 1 Preliminary Estimate DEXTER WILSON ENGINEERING, INC. PAGE 11 II-8.7 MANDATED WATER CONSERVATION MEASURES The State and many local Governments have mandated a number of water conservation measures. Table 4 summarizes the conservation measures that are currently mandated by the State of California and also provides the requirements proposed in the Draft 2010 California Green Building Standards Code. TABLE 4 MANDATED WATER CONSERVATION DEVICES Device Baseline Requirement 2010 Green Building Standards Code Showerheads 2.5 gpm 2.0 gpm Lavatory Faucets 2.2 gpm 1.5 gpm Sink Faucets 2.2 gpm 1.8 gpm Metering Faucets in Public Restrooms 0.25-0.75 gal/cycle 0.25 gal/cycle Residential Water Closets 1.6 gpf 1.28 gpf Flushometer Valves 1.6 gpf 1.28 gpf Commercial Water Closets 1.6 gpf 1.28 gpf Urinals 1.0 gpf 0.5 gpf II-8.8 LOCAL WATER CONSERVATION REQUIREMENTS There are a number of water conserving measures required by the Otay Water District and City of Chula Vista Landscape Manual. These include the use of recycled water for the irrigation of parks, median landscaping, open space slopes, and common landscaped areas where feasible. The Landscape Manual also requires some drought tolerant plant selection in the landscaping plan and the use of evapotranspiration controllers for parks and common landscaped areas. Additionally, the Landscape Water Conservation Ordinance that went into effect on January 1, 2010 is expected to reduce outdoor water consumption, particularly on single family residential lots. The City of Chula Vista Water Conservation Plan Guidelines requires the following three indoor water conservation measures for residential units and non-residential units. These measures are mandatory. DEXTER WILSON ENGINEERING, INC. PAGE 12 Residential Measures- Mandatory 1. Hot Water Pipe Insulation. This measure involves the insulation of hot water pipes with 1-inch walled pipe insulation and separation of hot and cold water piping. This measure is estimated to cost an additional $50 during initial construction and result in annual savings of 2,400 gallons per residential unit. 2. Pressure Reducing Valves. Setting the maximum service pressure to 60 psi reduces any leakage present and prevents excessive flow of water from all appliances and fixtures. This measure is estimated to cost $100 during initial construction and result in annual water savings of 1,800 gallons per residential unit. 3. Water Efficient Dishwashers. There are a number of water efficient dishwashers available that carry the Energy Star label. These units cost an additional $500 on average and result in an estimated yearly water savings of 650 gallons per residential unit. Non-Residential Measures- Mandatory 1. Hot water pipe insulation with 1-inch walled pipe insulation. 2. Compliance with Division 5.3 of the California Green Building Standards Code in effect at the time of plan submittal. 3. Pressure reducing valves. Non-Mandatory Measures In addition, to comply with the City’s current water conservation requirements, the developer must select at least one outdoor measure and one additional indoor or outdoor water conservation measure for residential development and non-residential development. Water conservation measures not included on the City’s Residential Water Conservation Measures list may be proposed by the developer. The developer will implement, from the City’s list of approved measures, the following two additional non-mandatory measures in single family residential units, multi-family residential units, and non-residential units. DEXTER WILSON ENGINEERING, INC. PAGE 13 1. Dual Flush Toilets. The developer will install dual flush toilets within the project. This measure is estimated to cost $200 per household and result in annual water savings of 4,000 gallons per year per residential unit. 2. Water Efficient Landscaping. The developer will comply with the City’s Landscape Water Conservation Ordinance to reduce outdoor water use. This will include selection of a more drought tolerant plant selection, including less turf area as well as installation of water efficient irrigation systems. While the estimated savings from this measure is difficult to quantify at this state of planning, it is estimated that outdoor water usage at single family residences will be reduced by a minimum of 10 percent, or 25 gpd. II-8.9 WATER CONSERVATION ESTIMATED SAVINGS The estimated water savings for water conservation measures are based on the estimates provided in Section II-8.8 of this report. The potential water savings varies widely based on land use types. Multi-family residential units, for example, have much less opportunity to implement additional water saving measures than low density single family residential units. This is primarily because the common landscaped areas of multi-family units are required to be irrigated with recycled water and, thus, there are no outdoor water conservation measures that can directly offset potable water usage in these areas. Tables 5 and 6 summarize the total estimated water savings for Village 8 West based on the proposed required measures and non-mandatory measures described above. DEXTER WILSON ENGINEERING, INC. PAGE 14 TABLE 5 VILLAGE 8 WEST MULTI-FAMILY PROPOSED WATER CONSERVATION MEASURES Measure Location Yearly Water Savings, gal/unit Daily Water Savings, gpd/unit Percentage of Total Usage1 Project Total Water Savings2, gpd Hot Water Pipe Insulation Indoor 2,400 6.58 2.2 9,400 Pressure Reducing Valves Indoor 1,800 4.93 1.6 7,040 Water Efficient Dishwashers Indoor 650 1.78 0.6 2,540 Dual Flush Toilets Indoor 4,000 10.96 3.6 15,660 Water Efficient Landscaping Outdoor ------ 3 --- ---3 TOTAL 8,850 24.25 8.1 34,650 1 Based on 300 gpd/unit average usage. 2Based on 1,429 Multi-Family Residential Units. 3 This measure will reduce the amount of recycled water used for irrigation and has, therefore, not been included in the total potable water savings. TABLE 6 VILLAGE 8 WEST SINGLE-FAMILY RESIDENTIAL WATER CONSERVATION MEASURES Measure Location Yearly Water Savings, gal/unit Daily Water Savings, gpd/unit Percentage of Total Usage1 Project Total Water Savings2, gpd Hot Water Pipe Insulation Indoor 2,400 6.58 1.3 4,090 Pressure Reducing Valves Indoor 1,800 4.93 1.0 3,060 Water Efficient Dishwashers Indoor 650 1.78 0.4 1,110 Dual Flush Toilets Indoor 4,000 10.96 2.2 6,810 Water Efficient Landscaping Outdoor 9,125 25.0 5.0 15,525 TOTAL 17,975 49.25 9.9 30,585 1Based on 500 gpd/unit average usage. 2 Based on 621 Single Family Residential Units. DEXTER WILSON ENGINEERING, INC. PAGE 15 Water Conservation Summary As detailed in this report, the Village 8 West project is committed to being water efficient through the use of recycled water for irrigation and utilizing other water conservation devices and measures. Table 7 summarizes the baseline potable water use if recycled water and water conservation measures were not utilized and provides the anticipated water savings outlined in this report. As shown, the use of recycled water and other water conservation measures is expected to reduce potable water usage by 202,490 gpd, or 21.9 percent. As evidenced by the information contained in this study, the objectives of the Otay Ranch GDP to incorporate water saving fixtures, drought tolerant landscaping, and recycled water usage into the development are being met. Based on information contained in the 1989 San Diego County Water Authority Annual Report, average water use within the Otay Water District was 220 gallons per day per capita (20,469.7 AF for a population of 83,000). Based on 2007 data from the OWD 2008 Master Plan, per capita water usage has dropped to approximately 189 gpd (33.26 mgd for a population of 186,000). These per capita numbers include non-residential demands, but clearly indicate the effectiveness that the above measures are having. This trend is expected to continue as adopted guidelines are increasingly focused on reducing per capita water use. TABLE 7 VILLAGE 8 WEST WATER CONSERVATION SUMMARY Description Average Use, gpd Total Water Use Potable Water Use (Table 2) 786,575 Recycled Water Use (Table 3) 137,270 Total Baseline Water Use 923,845 Water Conservation Savings Recycled Water (Table 3) 137,270 Multi Family Measures (Table 5) 34,650 Single Family Measures (Table 6) 30,585 Total Conservation Savings 202,505 Net Potable Water Usage 721,340 1 Reduction from Baseline Usage 21.9% 1Potable water use (Table 2) minus water conservation savings (Tables 5 and 6) DEXTER WILSON ENGINEERING, INC. PAGE 16 II-8.10 IMPLEMENTATION MEASURES The non-mandated water conservation measures to be included in the residential component of the Village 8 West project are listed in Tables 5 and 6. The non-residential development within the project will utilize hot water pipe insulation, pressure reducing valves, water efficient landscaping systems, and dual flush toilets as well as meeting all requirements of Division 5.3 of the California Green Building Standards Code in effect at the time of plan submittal. II-8.11 MONITORING For the water conservation measures proposed to be incorporated into the Village 8 West project, Table 8 summarizes the implementation timing for each measure, as well as the responsibility for monitoring the implementation of the measures. TABLE 8 VILLAGE 8 WEST IMPLEMENTATION AND MONITORING PROGRAM Water Conservation Measure Responsibility for Implementation Timing Monitoring of the Implementation Hot Water Pipe Insulation Developer Prior to Issuance of Building Permit City Building Department Pressure Reducing Valves Developer Prior to Issuance of Building Permit City Building Department/Otay Water District Water Efficient Dishwashers Developer Prior to Issuance of Building Permit City Building Department Dual Flush Toilets Developer Prior to Issuance of Building Permit City Building Department Water Efficient Landscape System Developer Prior to Issuance of Building Permit City Building Department DEXTER WILSON ENGINEERING, INC. PAGE 17 REFERENCES 1. Bahman Sheikh, Water Use Efficiency, Strategies for Proposed Residential Developments, September 2001. 2. City of Chula Vista Water Conservation Plan Guidelines, adopted May 27, 2003. 3. Chapter 20.12 Chula Vista Landscape Water Conservation Ordinance, (Ord. 3146) December 8, 2009. 4. Overview of Water Service for Otay Ranch Village 8 West, November 2010, Dexter Wilson Engineering, Inc. 5. Otay Water District Water Resources Master Plan, October 2008, PBS&J. 6. San Diego County Water Authority Annual Report, 1989. 7. California Green Building Standards Code, Draft 2010.