We invite you to attend our meetings, review the materials on our website, and contact us with your questions. We want to hear from you!
Woodland and Davis are two of only a very few cities in California that still rely entirely on groundwater for water supplies. In the past, groundwater was good and plentiful enough to meet community needs, and also state and federal water quality regulations. By itself, groundwater isn’t good enough anymore to meet anticipated state water quality and wastewater discharge regulations. The quality of local groundwater supplies is getting worse. Our groundwater has an increasing amount of salts and other minerals that threaten the environment and public health. The Cities cannot meet anticipated future regulations for the water coming into homes, or for water returned to the environment after leaving the wastewater treatment facilities. We can’t afford to wait. Delaying the project or doing nothing at all are not options.
The many benefits include health and safety of drinking water supplies, reduced costs from avoidance of wear and tear on water using appliances, compliance with treated wastewater discharge requirements, and environmental benefits associated with improvements to discharged wastewater. Resulting improvements in the quality of treated wastewater will increase the opportunity for water reuse, advance environmental stewardship in the Yolo Bypass, and potentially lower wastewater treatment costs from what they otherwise would be in the future.
It’s getting more and more difficult to meet demands for water use and water quality regulations using existing infrastructure. A number of groundwater wells in Davis and Woodland have been shut down and destroyed because they no longer work and can’t be fixed, or because they compromise drinking water quality. Even with major improvements to groundwater facilities (wells and pumps, for example), we would still fall short of meeting future water quality regulations for drinking water and treated wastewater. It’s the quality of the water – not the quantity – that’s driving the shift from groundwater to surface water. We need a higher-quality source of water.
An acre-foot of water – a common unit of measure for water – is about 325,000 gallons. That’s roughly the amount of water used by two households in a year, including landscape water use.
More aggressive water conservation can save money for both individual water customers and water utilities. Both Cities are well on their way to meeting the new State requirements for reducing per capita water demand by 20 percent by 2020. However, water conservation can’t improve water quality, and it will not reduce the salt content or eliminate other water quality constituents of concern in either the water supply or wastewater systems. Again, it’s the quality of the water – not the amount – that has created the need for the project.
The high, naturally-occurring salt content in the groundwater combined with additional salt from consumer uses (including water softeners) results in a high concentration of salts in the water. “Used” water that leaves our homes – also known as “wastewater” – has even higher concentrations of salt than the water that comes into our homes. For wastewater, the Central Valley Regional Water Quality Control Board (Regional Board) is aggressively pursuing requirements for reductions in salt discharges to protect the environment and other downstream water users. For example, consumers may be required to switch from salt-based water softeners (maintained by homeowners) to ion exchange-based water softeners (maintained by water softener vendors) that will add significant costs (about $42 per month). Discharges of treated wastewater in the Central Valley will have to meet more stringent salinity standards in the future. Switching to surface water should eliminate the need for water softeners.
Desalination – reducing the salt content in water or wastewater – is very costly (in fact, far more expensive than the Project’s costs), both for construction and operation. Even with emerging new technologies, desalination requires high amounts of electrical energy and expensive systems, and poses serious and costly problems with disposal of brine from the treatment process. To provide the most value, desalination would be needed at each individual groundwater well. However, many of the wells are in residential locations where there is not enough room to construct treatment facilities, including the storage and disposal facilities to handle the brine that would be a product of treatment. The amount of high-saline brine that would require disposal would be 20 percent or more of the volume of water being treated. This brine would need to be transported to an area closer to the coast for ocean disposal. It is expected that it would be very difficult, if not impossible, to get permits to implement all aspects of desalination, including brine disposal.
Water-rights permits will state the maximum amount of water than can be diverted from the Sacramento River every year, the maximum rate that it can be delivered during dry times of the year and in dry years. It is expected that these permits normally will not allow diversions during summer and other dry periods. During these times, WDCWA will utilize up to 10,000 acre feet of water under a senior water right purchased from the Conaway Preservation Group (see below).
WDCWA purchased a senior water right for 10,000 acre feet of surface water from the Conaway Preservation Group. This water is subject to fewer restrictions during dry periods and the summer months and will be used during those times when water under the Agency's primary water right is not available. Existing groundwater sources will continue to be used along with deeper–aquifer, higher-quality groundwater to help meet peak summer demands. Combined use of surface and groundwater sources, referred to as “conjunctive use,” and the blending of supplies will result in substantial year-round improvements in water quality, including the summer months.
Yes. Independent professional studies commissioned by the Davis City Council repeatedly confirmed this project as the least-cost option for meeting drinking water and wastewater quality regulations, and ensuring that water is always available when needed. A panel of nationally-recognized drinking water experts was convened in 2008 by the National Water Research Institute and their results were provided in a written report. A similar independent evaluation was completed in early 2009 by retired UC Davis engineering professors Ed Schroeder and George Tchobanoglous (click here to read the report).
Additionally, planning for the project over the past 20 years has involved a number of expert professionals, including: Bartkiewicz, Kronick & Shanahan; Bartwell Wells; Borcalli & Associates; Brown & Caldwell; BSK Engineers, Geologists, Environmental Scientists; Environmental Science Associates; Kennedy/Jenks Consultants; LTD Engineering; Larry Walker Associates; Luhdorf & Scalmanini; Montgomery Watson Harza; West Yost Associates; Winzler & Kelly; and Wood-Rodgers.
Even without new homes and residents, the Cities would still be required to improve the quality of their water. The regional water supply project is designed to provide water that meets state and federal regulations, not to encourage growth and development. Existing residents in both Cities will always need safe drinking water, and the Cities will always be required to meet water quality and wastewater discharge regulations, regardless of growth.
In December 2010, UC Davis entered into an agreement with WDCWA for a potential water supply contract. Should UC Davis decide to exercise its water purchase option, the agreement obligates it to pay “into” the Project for capital and fixed and variable operating costs. UC Davis, a long-time project partner, paid its fair share of Project costs through September 15, 2009, the date on which the Woodland-Davis Clean Water Agency was formed. Project costs incurred after that time will be assessed to UCD. Payment for UC Davis’ share of capital and fixed operating costs for the water treatment plant would be assessed at a rate equal to UC Davis’ share of the treated water. Operating costs for the transmission pipeline from the water treatment plant to Davis will also be assessed.
The size of the Project facilities does not change with or without UC Davis’ participation. If UC Davis exercises its water purchase option, the costs to Woodland and Davis would be decreased in proportion to UC Davis’ share of the treated water. If UC Davis does not exercise its option, its share of the treated water will be assumed by Woodland and Davis to cover future needs.
WDCWA's Board took actions today to reduce project costs by ...
Please attend a tour of proposed water supply project facility ...