Davis Water - Saving More Together

Contact Information

     1717 5th St. Davis CA 95616

Office Hours
Monday – Friday
8:00am to 5:00pm

Frequently Asked Questions

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Surface Water Project

General Water Questions

Water Operations

Wastewater Treatment Plant


Surface Water Project

How are the surface water intake and treatment plant funded?

The City of Davis is determining financing options for its portion of the water intake and treatment plant, but it will likely be 30-year bonds.

What is the regional surface water project?

In 2009, the cities of Davis and Woodland formed the Woodland-Davis Clean Water Agency (WDCWA), a joint powers authority responsible for building and operating a regional surface water supply project. The project will include a water intake facility on the Sacramento River, a regional water treatment facility, and new pipelines for water conveyance. Davis’ cost share of the project facilities is estimated at $156 million, although aggressive cost-savings activities and refinements to project plans may reduce costs.

The regional surface water supply project will bring customers softer water, ensure water supplies are reliable in the long-term, and help guard against potential land subsidence and the associated impacts and costs. The new water source may taste better to some customers and be easier on appliances, household plants, and landscaping. This water will be lower in salts and other constituents.

A 2007 Environmental Impact Report identified the surface water supply project as the environmentally superior alternative.

In December 2010, WDCWA purchased a site on the Sacramento River for an intake facility that will be jointly constructed, owned, and operated with Reclamation District 2035, provided that outside funding is provided. Otherwise, WDCWA may construct its own intake facility. The State Water Resources Control Board approved WDCWA's rights to 45,000 acre feet of Sacramento River water in March 2011. WDCWA has purchased the permanent rights to 10,000 acre feet of surface water from the Conaway Preservation Group, for use during times when diversions would not be allowed under WDCWA's own water rights. Design of the intake structure and water treatment facility is underway, and final environmental work is being completed.

For more information on the regional surface water project, visit a

Why did the Woodland Davis Clean Water Agency choose Sacramento River water instead of water from Lake Berryessa?

Water from Lake Berryessa water was only available in the 1950s and 1960s, and at that time the City chose not to participate in water rights acquisition. Water from Lake Berryessa is fully allocated and is no longer an option for the City of Davis.

How did the Woodland Davis Clean Water Agency determine that construction of the water intake structure and treatment facility would be completed by 2016?

timeline was developed to account for the environmental permitting and construction processes. The design-build-operate approach will help to deliver the project in a timely fashion.

What percentage of the surface water treatment plant cost is associated with environmental regulations?

The primary objective is to provide a reliable, sustainable, high-quality water supply for Davis. It will also improve water quality that will meet or exceed all current and future anticipated water quality regulations. All water regulations are driven by public health and environmental standards.

Are independent reviews of the proposed surface water project available?

Yes. Visit the Woodland Davis Clean Water Agency’s website:

How can interested residents review detailed analysis of project alternatives?

Project alternatives, along with other documents, can be found on the Woodland Davis Clean Water Agency’s website:

Is the project for water quality or supply?

Both. The project is designed to provide water supply reliability and improve water quality. Additionally, it will improve the quality of treated wastewater discharge.

Will the City use local firms for the construction projects?

Three large design-build-operate (DBO) firms have been pre-qualified and must compete for the project. Contracts will include provisions for local hiring.

Will the City provide incentives for on time completion?

That level of contractual detail has not been determined.

How does the City plan to finance its portion of the intake structure, treatment plant, and distribution system?

At this time, the City plans to use 30-year tax exempt bonds. It will also work through the JPA and independently to pursue state and federal grant funding, and low-interest loans for local improvements.

When would the City’s debt service begin?

Bond financing starts when the City acquires bonds.

How is Sacramento River water transported to the water treatment plant?

Untreated surface will be transported through 36-inch pipes to the treatment plant.

How will the surface water be treated?

The City has been testing Sacramento River water at the location of the intake facility for several years. The water treatment plant will be designed specifically designed to address and treat constituents found in the River water.

Will pumping stations be used?

Yes. Gravity will transport treated water to the water treatment facility, then it will be pumped to the cities.

How has the City looked to save money on this project?

Davis has recognized an immediate cost savings by partnering with Woodland, sharing costs that would otherwise be borne entirely by Davis. The initial phase of the water treatment facility has been sized for near-term water use projections. The City has also closely monitored other cities transition from a single water source and has learned from choices made. Using the design-build-operate and proposing to construct during this competitive bid time are also cost saving measures being utilized.

Will there be an additional charge to pay for the financing of the project?

All charges have been factored into the proposed water rates.

Does the City’s water permit for Sacramento River water state how much the City can draw?

Yes. The permit was issued to the Woodland Davis Clean Water Agency and includes provisions for 45,000 acre feet per year, to be shared by Woodland and Davis.

How does the cost of the Conaway Ranch water compare to the cost of the water that Northern California sells to Los Angeles?

Each water provider has its own contracts outlining the amount of water used and the costs. The Woodland Davis Clean Water Agency obtained very competitive pricing on the Conaway Ranch water of $260 per acre foot of water. After 23 annual payments, the JPA will own the water outright and will no longer be obligated for payments.

Could the cost of the water supply project change?

The cost of the project could increase or decrease, but staff has planned a contingency should the costs actually change. The exact cost will be determined once competitive bids from contractors have been received.

How will a change in project costs affect water rates?

As the final cost is determined, water rates could be adjusted. The water rates as approved by Council are the maximum possible rates that could be imposed.

Is the University of California, Davis part of the Woodland Davis Clean Water Agency?

University of California, Davis is a participating agency, but does not hold voting rights. UC Davis has the opportunity to buy into the water supply project.

Will the City of Davis pay for $155 million of the water supply project?

The City will pay its share based upon the final project costs, which include portions of the regional water treatment plant and intake structure, the cost of the infrastructure to transport treated water to Davis customers, and improvements to local facilities (pipelines, for example).

Does the Woodland Davis Clean Water Agency have the required permits to pull water from the Sacramento River?


Will the required permits expire?

The permits require the permit holder to use the water for beneficial use. If the water acquired through the permit is not used, it would no longer be considered “beneficial use” and the permits could be revoked.

What is the cost of the permit?

There is an administrative cost to apply for the permit, but once obtained there is no cost to divert the water from the Sacramento River. Costs are only associated with the construction, treatment, and distribution of the water.

What growth was figured into the water supply project?

The City of Davis Council uses a growth rate of one percent for planning, and that was also used for the project.

What is a DBO contract?

DBO stands for Design Build Operate. This process allows all phases to take place simultaneously, thus reducing costs and time. The engineer will design the plant, with input from the contractor that will build it and the operator that will operate it. All members of the DBO team work together to ensure efficiencies.

Will stimulus money be used for this project?

Not at this time. In 2009, the City tried unsuccessfully to obtain federal funding. The City and the Woodland Davis Clean Water Agency will continue to seek outside funding.

What will happen to the water right permit if the project is delayed?

The State requires water to be used for reasonable and beneficial use. A delay could result in a reevaluation of the permit.

Will all City of Davis water users use surface water?

Yes. During peak use, specifically in the summer, the surface water will be combined with small amounts of groundwater to meet demands.

Will the Sacramento River water still be available to the City of Davis during drought years?

The City will continue to use the surface water and combine it with a small portion of groundwater from the deep water aquifers as needed, giving Davis the flexibility to meet demands.

What is conjunctive use?

Conjunctive use in relation to water means combining water from different sources, like surface and groundwater, for beneficial use.

Will treated surface water be provided to South Davis?

Yes. Treated surface water will be provided to all City of Davis water customers.

How does risk management apply to the City of Davis’ evaluation of the surface water supply project?

Because regulations are increasing more stringent, the City of Davis must consider current and future regulations and plan accordingly. The City employs risk management strategies to allow for the ability to retrofit facilities to meet future regulations.

General Water Questions

How do I know if I have a leak, where can I get help?

If the water usage on your utility bill is higher than average, you may have a leak in your home or on your property. The Public Works Department provides leak checks free of charge by calling 757-5686 or e-mailing Public Works staff will check for continuous use at the meter and contact you with their findings.

Do rate payers have the opportunity to look at water use online?

Water users can view their water use online through the WaterInsight program. Your account can be activated through this link.

What would the City need to invest if it continued using wells?

The City will continue to use the deep aquifer wells to supply peak demand in the summer months. A portion of the rate increase is dedicated to current system upgrades and deferred maintenance. Intermediate wells could be used for irrigation of public areas. However, using wells alone will not meet the City’s long-term objectives of improving water supply reliability, water quality, and treated wastewater discharge. Additional modifications would have to be made to the wastewater treatment plant, increasing the cost of that project.

What is the downside of the City using deep wells instead of treated surface water?

Using deep wells will not allow the City of meet its long-term objectives for improving water supply reliability, water quality and treated wastewater discharge. Currently, the City operates six deep wells and 15 intermediate wells. The intermediate wells pose more challenges for the City as they have more salinity and other constituents that affect the City’s wastewater discharge. Another problem associated with relying on wells is that the City is operating a single-source system. Should something happen, the City does not have a second source of water to provide to its customers. And, the deep aquifer is also used by UC Davis. It’s unknown exactly how much water, and for how long, it is naturally available from that aquifer.

What percent of water consumption is actually used as drinking water?

Approximately 2-3 percent of Davis water is used for drinking.

How does the deep water aquifer get replenished?

It’s replenished by runoff from the Vaca Mountains. If we continue to drill into the deep aquifer, we run the risk of using more water than is being replenished.

Once the City begins using surface water, will there continue to be a need for water softeners?


How will using surface water reduce the need for softeners?

Surface water has lower hardness levels than groundwater, which the City currently uses.

Has the City considered using recycled water?

Yes, and opportunities for incidental use are being explored. On a large scale, it is cost prohibitive because a delivery system would need to be installed to each water user throughout the City. In other cities where recycled water is used, the City planned for it and included the “purple pipe” water delivery system at the time of construction. That was not done in Davis. However, the City is exploring opportunities for use of reclaimed water.

Does the City of Davis restrict the use of water softeners?

The City has taken the position that it does not want to regulate the use of water softeners. Instead, it prefers to provide residents with the information necessary to make educated decisions.

When can City of Davis residents stop using water softeners?

The goal is to have the water supply project online in 2016, and at that time the need for water softener use will decrease.

When the City of Davis drills new deep water wells, is water always reached?

The City completes test wells prior to drilling and will not construct wells in areas where water is not found. The purpose of test wells is to ensure that water will be reached when the final well is drilled.

Do any other jurisdictions tap into the deep well aquifer used by the City of Davis?

The University of California, Davis uses the same deep well aquifer as the City of Davis. No other jurisdictions currently use the aquifer.

How large is the deep water aquifer used by the City of Davis?

Research is inconclusive, but it does demonstrate that Davis and UC Davis share the same deep aquifer, and that the City’s use of that aquifer impacts UC Davis.

How much water does the University of California, Davis use annually?

Approximately 2,000 acre feet.

How much water does the City of Davis use annually?

Approximately 12,200 acre feet.

How much surface water will the City of Davis use annually?

The Woodland Davis Clean Water Agency has obtained permits to divert up to 45,000 acre feet of water from the Sacramento River each year. Of that, the City of Davis can use up to 20,000 acre feet annually.

Will Davis water users continue to need to use water softeners if surface and groundwater will be combined during peak use?

No. The City commissioned a study to ensure that the City will meet target goals for softer water once surface and groundwater are combined. This will eliminate the need for water softeners.

It appears that the City of Davis is one of the largest water users. How does the City plan to reduce its water use?

The City is studying various ways to reduce water use on City property. City parks are one of the largest users and irrigation wells are a possibility for future use.

Do potassium chloride and sodium chloride perform the same way?


What is the role of the State Water Resources Control Board?

The State Water Resources Control Board has authority over water allocation and water quality protection of California’s waters.

Who regulates Sacramento River water?

The State Water Resources Control Board allocates use and establishes policy, and the Central Valley Regional Water Quality Control Board establishes and enforces regulations.

Does the Department of Public Health base regulations on use?

The State Department of Public Health sets requirements for all water entering a home regardless of how the water user chooses to use the water.

Are any EPA regulations not met?

No. All State and Federal regulations are currently met.

Water Operations

What is the tank on Chiles Road?

That is a wellhead treatment facility, part of the City’s well 32. Water from that deep well exceeds maximum contaminant levels for manganese. The tanks are part of a manganese removal system that was required at the site.

What does the City of Davis do with the excess manganese that was pulled from the groundwater at the well heads?

Manganese will be transported to land near the WWTP for drying and ultimately disposed at the landfill.

How reliable is Davis’ current water supply?

City of Davis water currently meets all State and Federal guidelines. However, the City has had problems with several wells in recent years and those have been taken out of commission. Having a second water source will provide greater water reliability for Davis.

How many wells does the City of Davis use?

The City currently operates 21 wells, 6 of which tap into a deep water aquifer.

How deep are the City of Davis’ deep water aquifers?

Approximately 1,600 feet deep.

How will operations and maintenance costs change once the surface water treatment plant is online?

The total O&M costs for the City will increase with the addition of the surface water treatment plant. The cost for Well O&M will be reduced because we will be decommissioning some wells, but Davis’ share of the O&M cost for the surface water will be around $4M annually.

Wastewater Treatment Plant

Would it be more cost efficient to install reverse osmosis systems at each home in Davis?

No. The cost per gallon of water using the reverse osmosis system is approximately $0.13 per gallon, but the cost per gallon of water from the surface water project is approximately $0.01.

Has the City of Davis explained to the Regional Control Board that it is not possible to meet discharge requirements?

City staff and elected officials have met on many occasions with staff from the Board, and will also continue to communicate with the State about reasonable requirements. A Regional Control Board staff member attended the June 30 Woodland Davis Clean Water Agency Board meeting to discuss requirements.
The presentation can be viewed:

According to an article in the Davis Enterprise, the City of Davis could obtain a 10-year extension providing the City of Davis additional time to clean up its wastewater discharge. Is this true?

The Central Valley State Water Regional Control Board representative was improperly quoted in the Davis Enterprise article. He has indicated that the City of Davis could apply for an extension on the collection of fines, but would still be required to comply with regulations in a timely manner. Additionally, we could not guarantee that an application would be approved. An extension would be difficult to justify because the City of Davis has a viable, environmentally superior solution through the surface water project, and is not an economically disadvantaged community by state standards.

Does the State only review salinity discharge during summer months?

No. Salinity levels are based on annual averages.

Why are the sanitary sewer rates increasing?

Sanitary sewer revenues pay for the operations and maintenance of the collection system (pipes and pump stations that transport the wastewater from homes and businesses to the wastewater treatment plant), the wastewater treatment plant, and the administrative and regulatory costs to run the system. In addition, sewer rates support infrastructure investments, such as necessary system improvements to meet new regulations.

The City’s current National Pollutant Discharge Elimination System (NPDES) permit (issued by the US Environmental Protection Agency and State Water Resources Control Board) requires the City to make significant changes to its wastewater treatment plant in order to meet more stringent discharge requirements.

Over the last six years, the City has worked to identify the most cost-effective and prudent method for meeting the new discharge requirements. The nearly $100 million investment at the wastewater treatment plant will upgrade the plant to tertiary treatment so that the City can provide cost-effective wastewater services to its customers and protect public health and the environment.

How is my sanitary sewer rate calculated?

The sanitary sewer service rates are comprised of two components:

The fixed monthly charge is determined on the basis of the customer's classification. The variable charge is determined on the basis of each property owner's water use during the winter months because individual sanitary sewer flows are not metered; winter month's water usage best reflects actual flows into the sanitary sewer system, when outdoor water use is least likely to occur. This indicator of flow to the sewer is then applied to the variable cost of sewer operations. The variable charge is capped. If your average bi-monthly winter water use exceeds the cap, your sanitary sewer ccf charge shall be based on the cap.

Why is the sanitary sewer rate based on winter water usage?

Since the water meter measures total water entering a property, winter water usage is used to estimate indoor water use during the months of November through February when outdoor water use is much lower.

If the surface water treatment plant was not constructed, how would the City of Davis remove salt during the wastewater treatment process?

Currently, salt is not removed at the wastewater treatment plant. Doing so could cost twice as much as constructing the surface water treatment plant. Surface water is much, much lower in salinity than the City’s groundwater.

Has the City considered micro biological treatment of wastewater?

The City is already using this method and will use a more advanced version in the future.

What does the $100 million wastewater upgrade include?

The existing wastewater treatment process needs to be updated from overland flow system because it will not meet future regulations. The changes are based on public heath, impact to the natural environment, and protecting downstream water users. The upgrade will allow the City to produce a higher quality wastewater effluent which is necessary to meet current and future regulations.

When will construction begin on the wastewater treatment plant?

Construction is slated to begin in 2013 to capitalize on the current construction market.

Are the proposed wastewater treatment plant upgrades contingent on the surface water supply project?

Yes. The wastewater treatment plant upgrades could be different if the surface water supply project is not completed. The wastewater treatment plant upgrades would likely be much more expensive because groundwater would be used instead of the lower salinity surface water.

How much treated wastewater does the City of Davis discharge daily?

Approximately 5 million gallons of water daily.

What are the environmental impacts of high salinity levels in treated wastewater?

High salinity greatly impacts agriculture as well as many aquatic species.

Does the City of Davis’ treated wastewater reach any major waterways?

Yes. Davis’ treated wastewater is discharged into the Yolo Bypass and ultimately may reach the Delta because it is hydrologically connected.


Does the City offer a conservation incentive for wastewater rates?

The City is already providing incentive based billing for wastewater rates. Half of the wastewater rate is fixed, and the other half is based on water consumption. So, less water used would result in a lower wastewater bill.

Has conservation been factored into the proposed water rates?

Yes. The rates account for increased conservation.

Where can I find information on the City's water conservation program?

Information on the City's water conservation program can be found at

Where can I find more information?

Call (530) 757-5686 Monday through Friday from 8 a.m. to 5 p.m., or visit for more information on these and other utility services.