Your WaterFlood and Stream ManagementWatershed and Environment

wq-labMeeting and Beating the Standards

All of Zone 7's water delivered to its retailers serving homes and businesses in Livermore, Pleasanton, Dublin and Dougherty Valley meets state and federal health-related drinking water standards and, in almost all cases, the quality is much better than required. In addition, Zone 7 water meets most of the Agency's own, more stringent, water-quality targets.

ultrafiltrationplant_tour.jpgThese internal targets were developed for an additional margin of safety and to address local concerns regarding such things as taste, odor and water hardess. Zone 7's Water Quality Management Program -- developed jointly by Zone 7 and its stakeholders, including its water retailers -- establishes internal targets and policies for both treated and untreated water quality. These targets help guide operations and help provide a basis for upgrading or improving facilities and providing new facilities when necessary. In addition to ongoing internal agency planning, Zone 7 works closely with various organizations to protect the quality of source water locally and at the state level.

For various reports and planning documents addressing water quality, click here.

About Our Treatment Facilities

We operate three treatment plants at two locations.

Addressing Challenges

  • Surface water imported through the Sacramento-San Joaquin River Delta and conveyed via the South Bay Aqueduct, along with local runoff from Del Valle Reservoir, are the major sources of raw water supply for our surface water treatment plants. In recent years, treating this water supply with currently installed treatment processes at our treatment plants has become increasingly difficult due to more frequent algae blooms that can cause taste and odor problems, blue-green algae blooms that can produce algal toxins, high levels of organic matter, diurnal fluctuations in temperature and pH, and high alkalinity. Addition of the ozonation process at Zone 7’s treatment plants will enhance treated water quality and has been included in Zone 7’s Capital Improvement Planning and Asset Management Planning since 2006. Zone 7 is currently in the process of implementing ozonation at its treatment plants. Read more about the Del Valle Water Treatment Plant (DVWTP) Ozonation Project.
  • Groundwater typically has more minerals and is "harder" than surface water, but it is just as safe. Water becomes hard by picking up soluble minerals as it seeps through soil and rock into groundwater storage.
    • The Mocho Groundwater Demineralization Plant was opened in 2009 to slow down the buildup of salts and minerals in the groundwater basin per the Salt Management Plan portion of the Groundwater Management Plan, while improving delivered water quality.
    • For a fact sheet about hard water, click here.

Improvements on Tap

For information on planned water-quality projects over the next 10 years starting in the 2015-16 fiscal year, go to Zone 7's latest Capital Improvement Program document by clicking here.

Bottled vs. Tap?

Learn about the environmental, economic and other benefits of drinking tap water over bottled by clicking here.

aqueduct.jpg1/15/15: Urban Water Management Plan: Notice of Review and Potential Amendments. Click here.


Zone 7's surface water is comprised mostly of State Water Project water imported through the Bay-Delta, augmented by a small amount of other imported water supplies as well as runoff from local rainfall.

These surface supplies, some of which are stored in Del Valle Reservoir, are purified at Zone 7's treatment plants. When needed, Zone 7 also pumps water from the groundwater basin.

Zone 7 blends these sources for delivery to its water retailers, and stores surplus surface supplies in local and offsite groundwater banks for use during peak-demand periods and for reliability during droughts. The actual source of the water from your tap can vary depending on the time of year, rainfall levels and where you live in the Valley.

To view various reports and planning documents, click here.

Water Supply Evaluation

Zone 7 continuously strives to provide a reliable and high-quality water supply through the build-out of the Valley. The Agency's  Water Supply Evaluation [WSE] assesses the risks of a water supply shortage and is being used to help formulate a strategy for addressing projected shortages.

For a copy of the 2011 Water Supply Evaluation, click here.

The 2011 WSE evaluated a diverse set of water supply options for meeting the Valley’s water supply needs. One of these options is a regional desalination facility being developed in partnership with the Bay Area’s largest water supply agencies (EBMUD, SFPUC, SCVWD, and CCWD). For more information about the Bay Area Regional Desalination Project (BARDP), click here.



Once imported water arrives in the Livermore-Amador Valley, most is treated by Zone 7 for delivery to water retailers serving Pleasanton, Livermore, Dublin and Dougherty Valley, who in turn deliver it to you. Another portion of imported untreated water is used by Valley agricultural customers, and some is recharged into the groundwater basin for use when needed. Another portion of our Delta-conveyed water is sent to offsite groundwater-banking programs.




earthday_07.jpgZone 7's work in the area of environmental stewardship comes in many forms -- aimed at protecting not only our local drinking-water supplies and flood-protection channels, but also the overall environment and quality of life.

  • Our local watershed: Zone 7 helps protect, through management strategies, public education, community clean-up events, partnerships and other means, the watershed in order to reduce stormwater and other pollution in creeks. Click here.
  • Fisheries enhancement: Along with other Bay Area agencies, Zone 7 works collaboratively with the National Marine Fisheries Service on its development of strategies for fisheries enhancement to protect a threatened steelhead trout population. Click here.
  • Living Arroyos: This multi-agency partnership aims to enhance and maintain the urban streams and streamside habitats of the Livermore-Amador Valley, while continuing to protect drinking water supplies and prevent flooding. The program relies on active community support and involvement. Click here.
  • Addressing climate change: Zone 7 has been doing its part to address climate change by exploring ways to reduce dependence on fossil fuels for electrical energy used in our water-treatment and groundwater-pumping operations. Zone 7 also has begun planning ways to adapt its existing water-supply and flood-protection infrastructure to respond to greater climate variability in the future. Click here.
  • Energy efficiency: Zone 7 has taken many steps to improve energy efficiency in its operations, both to reduce its energy costs and help the environment. Click here.
  • Eastern Alameda County Conservation Strategy (EACCS): Zone 7 has worked with other local jursidictions, along with state and federal resource agencies, to develop a habitat conservation strategy for eastern Alameda County. It aims to provide a collaborative and consistent approach to preservation of the area's biological resources. The idea is to help coordinate and streamline mitigation requirements associated with various development and infrastructure projects (including Zone 7s water-supply and flood-protection projects), and to help base those mitigations on areas of strategic biological value. Click here.
  • Lake Del Valle Watershed Property purchase: Zone 7 recently purchased approximately 5,000 acres of rangeland near Lake Del Valle for the purposes of watershed protection:
  • Report a spill or dumping: For information on where to report a spill or dumping in a local waterway, click here.

Many of California's significant rain events are due to atmospheric rivers.  Read a KQED explanation of atmospheric rivers here.

Storm Central

  • The public can view the real-time stream flow data recorded by Zone 7's stream gauging network via the Storm Central website. To view it, go to: The link has been temporarily deactivated until close of business on Friday, February 15, 2019. 

Our Existing Flood Protection System

  • Zone 7 owns and maintains 37 miles of flood protection channels within a 425-square-mile area, about a third of all the Valley's channels and creeks. Read more...
  • As part of its flood management program, Zone 7 conducts many channel maintenance activities. Read more ...
  • Maps of Zone 7’s flood protection channels are available at the front counter of our administration building, located at 100 North Canyons Parkway in Livermore.

The  Stream Management Master Plan

  • Zone 7 has adopted plans for a new, more environmentally friendly way to provide flood protection to Valley residents and businesses. Read more...

What's New?

  • A listing of key Zone 7 Flood Protection and Stream Management projects.  Read more...

Flooding: What You Can Do to Prepare

  • Some of the Bay Area's worst flooding occurs in the late winter and early spring months. Here are some tips on how to prepare your home or property, including information on where to obtain sandbags. Read more...

Who Pays for Flood Protection?

  • Property taxes are the primary source of funding to operate and maintain the existing flood-protection system. Development fees pay for flood-protection system expansion. Read more...

Flooding History

  • Before Zone 7 implemented flood protection in the Valley, many areas were often covered with water during heavy rains. Read more ...