Residential/Irrigation Water Conservation Program

Through the Residential/Irrigation Water Conservation Program, the City of Foster City and Estero Municipal Improvement District are achieving water conservation results that will enable the City to develop and thrive.

City: Foster City


Water conservation is a constant challenge in California. The Estero Municipal Improvement District (serving Foster City and portions of San Mateo and governed by Foster City’s Councilmembers sitting as the EMID Board) found itself with a special need to achieve community-wide water conservation in 2009 when its water supply assurance (WSA) in non-drought years was negotiated to 5.9 MGD (million gallons per day).  Exceeding the WSA threshold could invoke a financially severe penalty equal to nearly 50% of the cost of water.


Foster City’s historic water use has varied from 5.0 MGD to 5.7 MGD, however, long-range water consumption projections anticipated a usage between 5.7 MGD to 6.1 MGD when planned development was factored in.  The City had to have the help of the whole community to successfully accomplish the development that would enable the City to thrive while ensuring adequate water supply for all customers.  In order to remain well under the cap, the District set a goal of 15-20% community-wide water conservation by 2020.


The challenge was finding a solution that was fair to customers, incentivized conservation to achieve water conservation goals, protected the beauty of our master-planned community, and avoided a complex administrative nightmare!

Narrative Solution

A 3-pronged approach has worked to achieve conservation goals:  1) education about the need and methods of conserving water; 2) conservation-based water rates that create financial incentives; and, 3) rebate programs that provide funds to install water-conserving fixtures and landscaping.


The education program included water-saving concepts and literature in water bills, information provided at community events, and specific outreach to customers that were using greater than 50% of the average use for their customer class.


Rebates are provided for high-efficiency toilets and washing machines, “smart” irrigation controllers, synthetic turf, turf removal and segregation of irrigation from domestic meters.


The biggest impact came through the conservation-based water rate model. Residential customers were assigned to one of three rate tiers whereby increasing levels of water consumption were subjected to higher rates.  A base level of consumption was established to achieve a 20% reduction in overall water consumption.  This base standard is the middle tier and was set at a maximum bi-monthly consumption rate of 20 CCF (hundred cubic feet) for single-family residential units and 10 CCF for multi-family residential units.  The tiered rates are 75% of base for those that use under 5 CCF (single-family) or 3 CCF (multi-family) and 150% of base for those that use over the Tier 2 maximum.


The biggest challenge was encouraging conservation among large irrigation customers without compromising the aesthetics of the community, a significant concern to this master planned community. Moreover, with 60% of the population living in multi-family residential developments, landscaping decisions are made for large irrigation areas by relatively few actors in the community. In order to preserve the ability of customers to maintain their landscaped areas while still conserving water, a Water Budget rate model was developed for irrigation customers. Landscaped areas were assigned a Water Budget based on size and type of areas, actual climate conditions, and evapotranspiration factors of plant materials.  Landscape Water Use Reports (LWUR) are issued each month to each irrigation customer, property manager, and landscaper to allow the customer to track budgeted use against actual performance, providing triangular accountability between those that use the water, manage the water budget, and ultimately pay for the water.  The actual performance is compared to the Water Budget on an annual “look back” basis, and penalties are assessed for water consumed over the water budget during the year.  Water budgets are managed by a contractor, which is paid through the Water Sustainability Fund created by the funds collected above the base consumption rate.


The District has a philosophy of matching its fixed costs with its fixed revenue sources (meter charges) and variable costs (water cost) to its variable revenues (consumption charges). Therefore, the District does not have to raise water rates as a result of customers conserving water.  Further, the District’s water costs are covered at the Tier 2 billing rate.  Revenues collected through the higher tier charges are put into a special “Water Sustainability Fund” which is used to pay for water conservation rebates and education programs for customers.

Narrative Results

The three-pronged approach of education, rates and rebates is working!  Overall water consumption is down 11.2% for residential and irrigation customers based on a review of the first 9 months of each year. 


Residential consumption is down 8.8% and irrigation consumption has fallen by 17.1%.  The difference between actual irrigation consumption and budgets has fallen by 49% since implementation of the program.  Nearly $300,000 in conservation rebates and educational programs has been distributed. 


Savings and Efficiencies/Improved Services

The City is the largest single water customer with sports playfields, parks, medians and buildings.  In Fiscal Year 2010-2011, 72 City accounts were identified as “overwatering.”  In Fiscal Year 2011-2012, that number was reduced to 6 accounts, helping to achieve conservation goals and also resulting in cost savings to the City.


Community Engagement

The District implemented the new rate structure as required by law with a notice mailed to all customers and a Public Hearing prior to rate setting.  The District held workshops and discussions prior to implementation of the rate structure.  Even so, there were numerous customer calls following the rate structure implementation.  Utility billing representatives helped customers understand both the rate structure and the resources available to help them conserve.  The interaction with customers indicated:


  1. The rate structure creates a financial incentive for heavy water users to change their consumption patterns.
  2. Once customers understand how their consumption pattern compares to those around them, most look at ways to change their patterns. 
  3. Water usage in the summer months, where outdoor usage is at peak, is critical in the overall plan for consumption.


For irrigation customers, water budgets were provided for Fiscal Year 2009-2010 with no penalties assessed so that customers could consider steps to achieve savings.  The water budget rates went into effect beginning Fiscal Year 2010-2011.  Customers receive reports monthly to enable them to monitor and adjust their use throughout the year.  The “triangular accountability” between property owners, property managers and landscapers has assisted in correcting overwatering behaviors.


Soon Foster City will begin significant public outreach on its new Sustainable Foster City plan, a blueprint for sustaining and enhancing the quality of life in Foster City.  Given that water availability is key to a sustainable community, that message will include how the community has been a part of the City’s success in ensuring water availability.



The Estero Municipal Improvement District Board and the Foster City City Council are identically composed, making the differentiation between the two entities slight.  The water conservation efforts of the District have a direct, positive impact on the City’s ability to achieve its development and infrastructure availability goals.


Measurable and Transferrable Results

Water consumption has measurably and significantly reduced in all affected categories.  This model is completely transferrable to any water agency that wishes to achieve similar water conservation results.


League of California Cities Strategic Priorities

The Water Conservation Program helps Foster City achieve its long-term development goals, which promotes Economic Development and provides reliable infrastructure upon which future generations can build.

© League of California Cities