As Santa Clara County endures its third consecutive year of drought, Valley Water is taking action to lead our region through the ongoing drought emergency and address the threats to our water supply.

On Friday, August 26, Valley Water convened a diverse cross-section of elected officials, business leaders, agricultural leaders, and environmental advocates from throughout Silicon Valley at the 2022 Water Summit to discuss our current water supply challenges and how we can partner together to address the drought and worsening climate change impacts.

Elected officials from the Cities of Campbell, Cupertino, Gilroy, Los Altos, Los Altos Hills, Los Gatos, Morgan Hill, Mountain View, Palo Alto, San Jose, Santa Clara, and Saratoga were among those who participated. Representatives from the Offices of Congresswoman Zoe Lofgren, Congressman Ro Khanna, State Senator John Laird, State Senator Bob Wieckowski, State Senator Dave Cortese, State Senator Josh Becker, Assemblymember Alex Lee, and Santa Clara County Supervisors Joe Simitian, Susan Ellenberg, and Otto Lee also attended the Water Summit.

Chair Pro Tem John L. Varela opened the Water Summit by emphasizing Valley Water’s commitment to partner with external partners on actions needed to help communities reduce their water use and help our region combat this drought emergency. The Water Summit featured a recorded keynote address from Senator Alex Padilla, presentations from Valley Water subject matter experts and partners in sustainability, and an expert panel discussion on how we can collaboratively work together to become more climate resilient. Valley Water subject matter experts presented on drought challenges due to climate change, actions taken in response to the drought, and strategies for a sustainable water supply into the future, as well as shared information on water conservation rebates and resources that can be used to help our communities get through this drought emergency.

Responses to questions received during and following the Water Summit are below.

1. If we're requiring more conservation, why are we allowing new connections and buildings? What are the cost implications for ratepayers from these projects?

Valley Water does not have land use authority to regulate growth and therefore cannot stop growth in the County of Santa Clara (County). Such land use authority rests with the County and individual cities that approve new development, such as housing, in their respective jurisdictions.

The Valley Water Board of Directors adopted the 2040 Water Supply Master Plan (Master Plan), which outlines Valley Water’s strategy for providing a reliable and sustainable future water supply through 2040. The Master Plan considered local general plan growth projections in its water demand projections and identified a water supply portfolio of diverse sources to meet future demands. The Water Demand Forecasting Methodology can be found in Appendix C.

The Master Plan water demand forecasts considered residential, commercial, industrial, and institutional growth using the Association of Bay Area Governments Plan Bay Area 2016 projections. The Water Demand Forecasting Methodology can be found in Appendix C. To meet the forecasted demands, the Master Plan identified a portfolio of diverse water supply projects. The Master Plan also describes a Monitoring and Assessment Program (MAP) which integrates new information and tracks changes to our existing water supplies (e.g., imported contract supplies, local water supplies, infrastructure, etc.), potential future water supply projects, and forecasted demands. For example, Valley Water updated its water demand model and reported the new demand forecasts in the MAP 2020 report. The MAP 2020 and 2021 reports both include new analyses of potential investment approaches to meet future water needs considering the updated demand forecasts. Links to past MAP reports presented to the Board can be accessed here.

Valley Water’s forecasted future demands also consider the long-term conservation we expect to achieve. When Valley Water completed its 2021 Water Conservation Strategic Plan, we found that: 1) the greatest potential for conservation continues to be outdoor conservation, and 2) increased participation for both indoor and outdoor conservation is needed to meet our long-term savings targets discussed in the 2040 Water Supply Master Plan. Water conservation is a key component of the water supply portfolio, and promoting and expanding water conservation is one of our strategies to meet future water demands.

To meet our level of service goal for the County through 2040, Valley Water continues to evaluate potential projects identified in the Master Plan. While some of them are costly, they enhance water supply reliability for the County. Through water supply master planning and other efforts, Valley Water continues to identify cost-effective projects and programs to provide safe, clean water now and in the future.

2. Regarding the Pacheco Reservoir Expansion Project, what evidence says the reservoirs will fill up and stay that way?

Inflows to the expanded reservoir would include a combination of natural inflows from the surrounding watershed and contract Central Valley Project (CVP) supplies transferred from San Luis Reservoir via the Pacheco Conduit. Based on historical data, annual natural inflow volumes from North and East Fork Pacheco Creek are estimated to range between approximately 50,000 acre-feet in wetter years to less than 50 acre-feet in the driest years, with a long-term historical annual average of 12,600 acre-feet. Annual volumes of CVP supplies pumped into the expanded reservoir would depend upon the following: annual CVP allocations; demands within Valley Water and San Benito County Water District (SBCWD) service areas; availability of other water supplies; storage levels in the expanded reservoir; and conveyance limitations of Pacheco Conduit. The annual volume of CVP supplies pumped into the reservoir would vary considerably depending on the identified considerations. Based on the Pacheco Reservoir Expansion Project Water Evaluation and Planning System (WEAP) model simulation under future conditions, results showed a range from zero acre-feet in a critical water year up to approximately 47,200 acre-feet in a wet water year.

This combination of sources could potentially produce about 100,000 acre-feet in a wet water year to fill a large portion of the 140,000 acre-feet of storage in the reservoir. Much more data and information on the hydrologic modeling can be found in Section 3.12 Hydrology and Water Management of the publicly available draft environmental impact report (EIR). The draft EIR can be accessed here.

3. Can you discuss how Valley Water and other agencies are using machine learning, remote sensing, and other new technologies in the water projects?

The California Department of Water Resources (DWR) is using remote sensing and other technology to support agencies like Valley Water that sustainably manage groundwater. This includes conducting regular satellite imaging to evaluate changes in the land surface. Valley Water uses this data, along with data from our own comprehensive subsidence (land sinking) monitoring network, to help ensure the risk of subsidence in Santa Clara County remains low. DWR is also conducting aerial electromagnetic (AEM) surveys of various groundwater basins. This involves a helicopter towing electronic equipment that sends signals into the ground, which supports continuous images used to interpret underground geology. Per DWR, “the process has been compared to taking a magnetic resonance image (MRI) of the ground’s subsurface.” Due to flight limitations near urban areas, only a small portion of Santa Clara County will be included in upcoming AEM surveys, but Valley Water remains excited about the use and results of this technology.

To support water supply planning, Valley Water is using remote sensing to better understand water and land use patterns throughout Santa Clara County. Through this, Valley Water can determine the types of irrigation technologies being applied and whether over-irrigation is occurring. Valley Water uses this information to support development of rebate and educational programs related to irrigation. We continually evaluate new modeling capabilities and how it can complement or expand our current modeling tools.

Examples of Remote Sensing:

• Valley Water uses hydrologic sensors and Supervisory Control and Data Acquisition (SCADA) meter data to help with both our water supply and flood protection efforts.

• Our water utility uses weather forecasting to operate Valley Water’s reservoirs during the rainy season, typically from November 1 to April 30. The weather forecasts inform our internal models that help us determine whether to capture the surface water runoff, which results from rainfall all over each watershed, or release the inflow to make room for forecasted, additional runoff that is coming our way. Remote sensing has the ability to measure variables like surface radiation value, atmospheric temperature, and wave conditions without the requirement for direct physical contact, and can be used to observe wind patterns and speed, detect wave currents, and the chemical concentration in the atmosphere.

• In our land surveying and mapping, Valley Water also uses drones (UAVs) for our percolation pond capacity surveys, which is remote sensing and a new technology. We also use sonar scanning and aerial surveys, both considered to be remote sensing, for our reservoir capacity surveys.

4. Does Valley Water anticipate water policies that make watering grass athletic fields at schools either illegal or financially unviable?

No, not at this time because athletic fields are considered "functional" turf. The State of California’s ban is only directed at non-functional turf, and Valley Water has adopted the State’s ban. Valley Water’s watering ban for commercial, industrial, and institutional (CII) turf, and the two (2) day per week limit on watering non-CII turf, both apply to non-functional turf. All landscapes are subject to Valley Water’s restrictions against runoff, midday watering between 9 a.m. and 6 p.m., and watering within 48 hours of 0.25 inch of rainfall. Valley Water’s Landscape Rebate Program offers resources and rebates to help reduce water use as well as comply with the ban. More information on the rebates available for converting turf to high-efficiency landscape or mulch, and for high-efficiency irrigation equipment can be found here.

5. With all the power outages, the lack of gas stoves will really be difficult. PG&E cuts off our power all the time. Without our gas stove, we would not be able to cook! Why is this law not considering this issue?

Valley Water is a water resources management agency. Our agency provides safe, clean water, flood protection, and stream stewardship, not natural gas and electric service. PG&E has a Help Center for inquiries here.

6. All know the drought is lack of moisture in ground. The elevated moisture in the air due to higher temperature, can be brought back to soil using an electronic cooling cycle. Solar power can power thermoelectric for bringing temperature decrease to dew point and thus green water generation. Green living starts with Green water, Green irrigation (pending patent) and finally Green HVAC. I am asking for fund for the Green water and green irrigation.

While Valley water cannot promote any one product, we encourage you to explore our Water Efficient Technology (WET) Rebate designed to help commercial, industrial, and institutional facilities implement equipment changes that reduce facility water usage. Facilities that install your product may be eligible to receive a rebate if measurable water savings can be shown. Pre-approval is required.

Valley Water’s Grants and Partnerships Program offers funding opportunities for schools, businesses, government agencies, nonprofits, and other organizations for any potential projects that support safe, clean water, flood protection, and environmental stewardship. Eligible project areas include water conservation, pollution prevention, volunteer cleanup efforts and education, wildlife habitat restoration, and access to trails and open space activities. More information can be found on

7. Given that we’re in severe drought, why is draining our Delta for a tunnel a good idea?

The Delta Conveyance Project is a single tunnel that will be operated to divert flows across the Delta during wet periods. Water will not be moved through the tunnel when river flows are low, and the fish and wildlife agencies will ensure that it is operated in a manner that is protective of sensitive fish species. Numerous climate projections indicate both wet and dry periods may become more intense and frequent in the future; if this is the case, the Delta Conveyance Project could help divert water during those high flow events for storage and use during dry periods. This would be a good idea for Santa Clara County because about 40% of Santa Clara County’s water supplies are conveyed across the Delta by the State Water Project and the Central Valley Project. The current Delta conveyance system is outdated and at risk of failing due to events such as sea-level rise, earthquakes, and flooding. Valley Water is evaluating the Delta Conveyance Project for its ability to mitigate those risks in a cost-effective manner. Valley Water has been engaged in and contributing funding to planning efforts to upgrade those Delta conveyance facilities since 2006 to safeguard those supplies.

8. Shall we “desertify” the greater Bay Area? How will that improve our state?

Through our Landscape Rebate Program and educational outreach, Valley Water encourages landscapes that are climate appropriate and need minimal amounts of supplemental irrigation. These landscapes would ideally be planted with local California native plants or suitable Mediterranean plants that could withstand periods of drought. While this approach is not desert-type landscaping, it encourages increased biodiversity, promotes soil health, and helps cool our air while still remaining drought tolerant.

9. Wouldn’t 100% recycling of waste water, as LA has committed to doing by 2035, make more sense, as that gives back millions of gallons every day? Senator Padilla says there funds for large scale recycle. Why is Valley Water promising merely to “improve” recycling from 5% to 10% by 2045?

Recycling wastewater requires partnerships with the agencies that treat wastewater in our county. Valley Water has been supporting our wastewater partners since the 1950s in their water recycling efforts, and is a leader in expanding water recycling. Valley Water operates the Silicon Valley Advanced Water Purification Center, the largest water purification facility in Northern California. This facility produces eight (8) million gallons of purified water per day, which is used to improve the quality of the recycled water for industrial and landscape uses. The Water Supply Master Plan (WSMP) recommends developing at least 24,000 acre-feet per year (AFY) of potable water reuse in addition to the target of 33,000 AFY of non-potable reuse by 2040. Valley Water’s Countywide Water Reuse Master Plan (CoRe Plan) evaluates potable reuse expansion throughout Santa Clara County, and identifies options to achieve the WSMP’s reuse targets. In 2020, the Valley Water Board of Directors directed staff to implement the Purified Water Project, the first potable reuse project in the County and the largest in Northern California by 2028. Valley Water advocated for creating a new program to support large-scale water recycling projects, which Congress included in last year’s Bipartisan Infrastructure Law. This program received $450 million for large-scale projects like Valley Water’s Purified Water Project, and we plan to apply for those funds when they become available. Valley Water is actively pursuing available grants to support the Purified Water Project.

10. What is the magical source for Pacheco reservoir? If water isn’t falling from the sky, how will the dam be filled? If temperatures are hotter, won’t surface water evaporate?

The water source for the Pacheco Reservoir will be a combination of local water from the watershed and imported water from the San Luis Reservoir. Because Pacheco is an emergency water supply source, water will be accumulated from the local watershed and transferred from the San Luis Reservoir during “wet” years (years of above average precipitation where existing local storage is insufficient to capture all available surface water). This water will then be utilized during drought years to offset water demands. With climate change creating more erratic weather patterns and increasing the likelihood of flooding and drought, it is imperative to capture the water when it is available. Pacheco Reservoir, like all open-air reservoirs, will be affected by evaporation. However, evaporation losses do not outweigh the benefit provided by the reservoir and can be combatted by replacing any water losses in wet years.

11. Given that open water reservoirs are low and, when temperatures are high, water evaporates from open water surfaces, does it make sense to build more huge surface reservoirs? Would’ve it make more sense to save water underground as well as in small, distributed-statewide, surface areas such as in naturally restored creek and stream banks, swales, etc.?

Valley Water conjunctively manages our surface water and groundwater supplies to ensure a sustainable water supply for Santa Clara County. This system includes 10 surface reservoirs, three (3) groundwater management areas, 3 drinking water treatment plants, over 100 off-stream groundwater recharge ponds, and hundreds of miles of instream recharge (recharge in creeks and streams) that benefit groundwater supplies and aquatic habitats. We also store water in an out-of-county groundwater bank in Kern County and in San Luis Reservoir in Merced County. Our diversity of facilities that include surface water and groundwater storage help Valley Water stay nimble in our drought response by increasing our control in the timing of available water and where it can be recharged or treated. Valley Water maximizes storage in local groundwater basins but continues to explore additional supplies and/or storage facilities.

To protect against the subsidence risk and ensure we have sufficient supplies to meet future demands, our Water Supply Master Plan 2040 investment strategy is to secure our existing system; invest in potable reuse, stormwater capture and conservation; and increase our operational flexibility through new conveyance and/or diversifying our out-of-county groundwater storage bank (i.e., so that we have water in more than one bank). To support stormwater capture, Valley Water is evaluating implementing a flood-managed aquifer recharge program (Flood-MAR). Flood-MAR captures and recharges stormflows off hillsides and from waterways on open space or agricultural fields. To help diversify our out-of-county groundwater storage, we are looking at several different out-of-county groundwater banks as well as expanding storage in existing surface water reservoirs regionally and locally. Each project has its own set of opportunities and constraints that Valley Water will carefully weigh when making investment decisions, including the impact of increasing temperatures on water supply volume and quality as well as benefits to wildlife and recreation.

12. In other, arid parts of the world, farmers grow chickpeas, lentils, fava beans, wheat, barley, sorghum, and more. Farmers in California do have options. They don’t need to wait for rain that may never arrive. Would it not make sense to shift toward such crops, in addition to using drip irrigation?

In Santa Clara County, agriculture only comprises approximately 8% of the water used in our county, a much lower rate than that in other areas of the state. Valley Water encourages efficient water use for all sectors, including agriculture, and offers resources to help growers reduce water usage. Our Agricultural Mobile Irrigation Lab (MIL) improves farm efficiency by offering free irrigation system evaluations, seasonal irrigation and soil moisture monitoring, and scheduling decision support. The MIL also provides irrigation system design consultations to help growers improve their systems, whether it be upgrading to or improving drip irrigation, which is widely used in the County, or improving overhead irrigation systems for crops that require it. Valley Water is a water resources management agency; thus, we do not provide recommendations on crop types to plant. We strive to manage water supplies for all beneficial uses, including agriculture.

13. I saw that comparing June 2022 to June 2019 saw a 9% savings in the summit presentation, but in a document online it said the cumulative water savings since the reduction call in June 2021 through June 2022 is 3%, compared to 2019. Could you help clarify this? Also, how does this fit in with the statement that water use was reduced 25% over the past five years? Is that per capita or overall?

Valley Water may use different baselines/approaches to calculate water conservation depending on the type of assessment needed.

To clarify, the amount of water used in Santa Clara County in June 2022 was 9% lower than the amount used in June 2019.

June 2021 is the month when Valley Water called for Santa Clara County to reduce water use by 15% compared to water use in 2019. The amount of water used in Santa Clara County from the period between June 2021 through June 2022 is 3% lower compared to the County’s overall water use in the same months in 2019.

In Santa Clara County, water use was 148 gallons per person per day in 2017 and 111 gallons per person per day in 2022. This represents a 25% decrease in per capita water use over the last five (5) years.

14. Are there any graywater programs to encourage appropriate graywater use for commercial/industrial facilities? I'm really especially focused on home projects and what individuals and families can do to build their own greywater systems, but one thing where I noticed an absence was: are there any efforts to encourage greywater use for commercial and industrial facilities?

Through the Graywater Rebate Program, Valley Water offers a rebate to residents who install a graywater laundry-to-landscape (L2L) system in their single-family homes. Residential L2L systems are simple to install, easy to maintain, provide a cost-effective drought proof source of irrigation water, and do not require a permit; graywater systems for commercial or industrial facilities are much more complex as they require storage tanks, filtration systems, pumps, and permits. Although residential L2L graywater systems have been in use for 20+ years, larger commercial grade graywater systems are still an emerging sector. Greywater Action is a great source of information related to graywater, including commercial scale graywater systems.

Commercial and industrial facilities are also encouraged to explore our Water Efficient Technology (WET) Rebate designed to help facilities implement equipment changes that reduce facility water usage. Rebates are based on measured water savings, and must save at least 100 CCF per year to be eligible for rebate (1 CCF = 748 gallons). Pre-approval is required.

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