Water Neutrality Guidebook
Water neutrality is a concept that aims to balance the quantity of water used or consumed with the amount of water restored or replenished. A reliable minimum supply of potable water is essential to the public health, safety and welfare of the people and economy of the Estero Municipal Improvement District.
On May 1, 2023 the City of Foster City and the Estero Municipal Improvement District Board of Directors adopted a Water Neutrality Ordinance to implement water reduction regulations for applicable future and new developments to ensure that new development(s) does not adversely affect the City's water supply. The Ordinance requires new development(s), redevelopment or changes in use within the EMID service area that will require a new water service or will increase water demand above the existing water demand level to offset the projected water demand with water efficiency/conservation/retrofit measures to create a neutral impact on the overall water use demand.
Permit Process
Process for Demonstrating Water Neutrality
Step 1: Obtain Baseline Water Demand for the subject property.
Staff to provide the applicant with the existing property’s Baseline Water Demand which is the average water use over the previous five-years from the date the building permit application was submitted. This would be the baseline to compare the Projected Water Demand. Where no water data is available, the Baseline Water Demand would be the five-year average of properties in the same customer class as the existing use or previously existing use with the same meter size, as determined by staff.
Step 2: Calculate and provide a Projected Water Demand at the time of planning entitlements.
The applicant to provide a preliminary Projected Water Demand as part of the entitlements. Projected Water Demand refers to the total amount of projected water demand for the proposed new development.
Step3: Projected Water Demand calculation shall be verified at Building permit submittal. If the proposed development has revisions from the approved set of plans from entitlements, the applicant to provide a revised Projected Water Demand spreadsheet during the plan check submittal to the Building Division. The applicant would also submit a calculated New Water Demand which is the Baseline Water Demand less the Projected Water Demand:
New Water Demand = Baseline Water Demand – Projected Water Demand
If a development is designed to use no more water than the property’s Baseline Water Demand, the project’s New Water Demand would be approved. However, if the Projected Water Demand exceeds the property’s Baseline Water Demand, the applicant will propose onsite and/or offsite water efficiency/conservation/retrofit measures to offset the New Water Demand.
Step 4: Complete onsite and/or offsite water efficiency measures to offset the New Water Demand.
For questions please contact the Planning Division at 650-286-3225.
Water Neutrality Calculator
Water neutrality shall be demonstrated through quantitative water analysis of the project based on the following calculations:
1. Request the baseline water demand from Staff (5-year average).
2. Calculate indoor and outdoor water allocations for the project site based on occupancy. If the project site’s water demand/usage is less than the allocations, the applicant will get a water conservation credit toward new water demand.
3. Calculate projected water demand.
4. Apply water conservation credit as applicable.
5. Establish new water demand/water offset requirements using the formula below.
New Water Demand = Projected Water Demand – (Baseline Water Demand + Water Conservation Credit)
The new water demand would establish the water offset requirement for the project.
Examples of Water Neutrality Measures
Water Conservation Rebate Programs
EMID water customers have access to various rebates to assist with water reduction.
Onsite Water Efficiency Measures
The applicant would be required to implement onsite water efficiency measures to offset the New Water Demand. This may include, but is not limited to, the following measures:
- Using alternative water sources such as graywater or rainwater.
- Instant hot water heaters.
- Pressure Reducing Valves (PRVs) to prevent the higher pressure from rupturing valves or pipes.
- Installing ultra-high efficiency plumbing fixtures and appliances that exceed current regulatory flow rates.
- Covers for swimming pools and spas.
- Automatic-fill valves would not be used with water features, including but not limited to swimming pools and ponds.
With regard to building and landscape design and operation, the applicant would still be required to comply with existing EMID and City of Foster City regulations including:
- Foster City Code Chapter 13.12 Stormwater Management and Discharge Control
- EMID Code Chapter 8.60 Water Conservation and Rationing
- EMID Code Chapter 8.70 Indoor Water Use Efficiency
- EMID Code Chapter 8.80 Outdoor Water Conservation in Landscaping
Off-Site Water Efficiency Measures
If a new development is designed with all practical onsite water efficiency measures and additional New Water Demand is still projected, the applicant would be required to explore off-site water efficiency measures to achieve water neutrality. The applicant may conduct off-site water efficiency measures including, but not limited to, direct installation of ultra-high-efficiency toilets and other plumbing fixtures, turf replacement, and commercial, institutional, industrial appliance upgrades within the EMID service area.
Resources
Water Neutrality Ordinance and History
The City of Foster City and the Estero Municipal Improvement District Board of Directors adopted Ordinance No. 138 that went into effect on May 1, 2023. See Chapter 8.90 Chapter 8.90, Water Neutrality Growth within Title 8, Water and Sewer Service of the EMID Code.
History:
On May 22, 2023 the President and Members of the Estero Municipal Improvement District (EMID) Board of Directors approved Resolution 2023-48 approving the Water Supply Assessment (WSA) Report for the Final Environmental Impact Report (EIR) for the Housing and Safety Elements Update.
A WSA is required for a proposed residential development of more than 500 dwelling units. The requirements for the WSA is described in the California Water Code Sections 10910 through 10915, amended by the enactment of Senate Bill 610 (SB 610) in 2002. SB 610 requires an assessment of whether EMID total projected water supplies available during normal, single-dry and multiple-dry water years, during a 20-year projection, are sufficient to meet the projected water demand associated with the 2023-2031 Housing Element, in addition to existing and planned future uses in the EMID service area (see Water Code Section 10910(c)(3)).
The WSA concluded that there is not “sufficient water supply” (per Government Code 664737.7 (a)(2)) available to meet the demands of the 2023-2031 Housing Element, in addition to the existing and planned future uses evaluated in this WSA, during single-dry and multiple dry water years within a 20-year projection. Water reduction strategies were identified in the WSA such as a Water Neutrality Growth Policy. (May 22, 2023 staff report link)
May 15, 2023 the EMID Board adopted Resolution No. 3721 approving the Water Supply Assessment (WSA) report for the Final Environmental Impact Report (EIR) for the Housing. (May 15, 2023 for staff report link)
On May 1, 2023 EMID Board approved an Ordinance adding a new Chapter 8.90, Water Neutrality Growth within Title 8, Water and Sewer Service of the EMID code. (May 1, 2023 staff report link)
On March 20, 2023 EMID Board approved Resolution No. 3713 directing staff to prepare an Ordinance implementing a Water Neutrality Growth Policy framework, as a long-term water demand management measure. (March 20, 2023 staff report link)
