Case Study Sept 2023: ‘Small but Mighty’ Soquel Creek Water Answers Threat to Groundwater Supply

  • by ACWA Staff
  • Sep 15, 2023
  • Newsletters

SqCWD employee Amanda Bunte conducts a water quality sampling test. The district relies on an array of methods to measure the impacts of seawater intrusion into its groundwater, which provides 100% of the district’s water supply.

Called “small but mighty” by its staff, the Soquel Creek Water District (SqCWD) in Santa Cruz County has attracted international attention while persevering in the face of daunting challenges. 

Not too long ago, the Central California Coast district faced the impending loss of most, if not all, of its most productive groundwater wells for drinking water through seawater intrusion. But in a classic example of measuring a problem to manage it, SqCWD today is slowing the pace of that intrusion through a mix of conservation, pioneering mapping technology and plans to accelerate progress through water recycling.

The situation looked dire in 2014, when SqCWD General Manager Ron Duncan learned that seawater could hit their main well field in three years with current levels of pumping. 

“We realized that if we didn’t do something, we’re done. We’re just done, and we’ve failed as stewards of our community’s water,” Duncan said. 

Cutting water use was an obvious strategy, and the district has since worked with its customers to reduce residential water use from 80 to 55 gallons per day. The basin SqCWD relies on is one of 21 critically overdrafted basins in California under implementation of the Sustainable Groundwater Management Act, or SGMA. 

Addressing the problem required getting a much more precise picture of exactly where seawater was seeping into the basin offshore, essential to understanding the immediate risk to coastal wells from seawater contamination. But how to get that picture remained unknown, until a call from halfway around the world.

When Duncan picked up the phone five years ago, the caller identified himself as being from the Danish embassy. Duncan thought it was a prank and hung up.  But when he called again, Duncan listened. Denmark, no stranger to understanding the mysteries of groundwater, had utilized airborne mapping technology to map and characterize its country’s groundwater systems. Its U.S. embassy had heard of SqCWD’s situation through its efforts to engage American water suppliers with its nation’s water-related technology sector. 

SkyTEM

Duncan’s telephone conversation led to the Danish-based companies SkyTEM and Ramboll in 2017 deploying what was then cutting-edge mapping technology along the Monterey Bay. This included SqCWD’s territory and the surrounding coastal region, covered by the Santa Cruz Mid-County Groundwater Agency, which coordinated the research work.

With SkyTEM, a low-flying helicopter can criss-cross over land or water towing a hexagon-shaped electromagnetic device that beams radio waves at the surface and measures the response. Ramboll’s website compares it to taking an MRI of the ground’s subsurface. The technology, in SqCWD’s instance, could also peer 600-feet beneath the ocean surface and into the seabed to collect data, which produced 3D image modeling showing exactly where seawater was seeping into the groundwater supply. 

Today, the technology is well-recognized and being used across California and the U.S. However, this mapping technology got its early start on California’s Central Coast and gave SqCWD what it needed to move forward in addressing the threat of seawater intrusion.

“Now, we know our sense of urgency. It is defined,” Duncan said.

Pure Water Soquel

SqCWD analyzed water supply solutions and determined the most effective option would be using purified recycled water to bring its basin into sustainability. Today, construction of Pure Water Soquel is on track for completion in late 2024. When it goes online, the facility will capture and purify through advanced water technologies about 25% of secondary effluent from the region’s wastewater treatment plant. Typically discharged into Monterey Bay, that water, once purified, will be conveyed to three Seawater Intrusion Prevention Wells to replenish the groundwater basin and create a barrier against seawater intrusion.

Funding for Pure Water Soquel included $63.25 million through California Proposition 1 and a $29.9 million grant through the federal WaterSMART Title XVI program, in addition to other funding sources. However, a big part of the project’s successful start cost far less.

Laying the groundwork for Pure Water Soquel, SqCWD recognized the need for a comprehensive public education campaign to increase its community’s understanding of purified water as a safe, reliable and sustainable supply of drinking water. As part of that campaign, SqCWD developed a mobile education trailer outreach effort on a shoestring budget of less than $8,000. SqCWD staff have driven the trailer throughout the community, including visits to farmers markets, Earth Day events and school presentations.  

International Attention

The educational campaign and its butterfly logo earned awards from the WateReuse Association and California Association of Public Information Officials. However, the Pure Water Soquel project as a whole received international attention in 2022 when BBC StoryWorks selected it as one of 16 projects worldwide, and among two in the U.S., for its mini-documentary video series, “Beneath the Surface, The Journey of Water.” The documentary can be viewed by scanning the QR code on the opposite page. 

For SqCWD, the documentary framed the success of a years-long effort to overcome what remains a serious threat from seawater intrusion, but a threat where an effective solution is now on the horizon.

“This mini-documentary points to our valued partnerships, which are crucial to successfully implementing this groundwater replenishment project. That includes the City of Santa Cruz, as well as the Santa Cruz Mid-County Groundwater Agency and especially our community as a whole,” SqCWD Board President Carla Christensen said. “Our partnerships also extend to the state and federal levels, which have provided generous grants and low-interest loans to help build Pure Water Soquel. From the Board to staff and our community partners – we are all in this together to ensure that our water supply is sustainable for current and future generations.”

Suggested Resources

15 RESOURCES prev next
Climate Resilience Bond Coalition Letter

To: California Legislators Subject: Climate Resilience Bond Coalition Letter Letter excerpt: The Association of California Water Agencies (ACWA) and the […]

Coalition Budget Letter – Oppose Funding Reductions for Voluntary Agreements

To: Governor Newsom, Senate Pro Tem McGuire, Assembly Speaker Rivas Letter excerpt: On behalf of the Association of California Water Agencies […]

Priority Issues Bulletin

Sorry, but only ACWA members have permission to view this content. Member login is required.

Comment Letter – Proposed Making Conservation a California Way of Life Regulation

To: State Water Resources Control Board Subject: Comment Letter – Proposed Making Conservation a California Way of Life Regulation Letter excerpt: […]

ON DEMAND: 2024 Spring Conference

ACWA’s 2024 Spring Conference ON DEMAND! Thank you to all those who participated in ACWA’s 2024 Spring Conference. This unique […]

ACWA 2024 Spring Conference Presentations

Presentations from ACWA’s 2024 Spring Conference & Expo held May 7-9 in Sacramento are available below. Please note that this […]

ACWA 2024 Spring Conference Attorney Programs

Presentations from the Attorney Programs held during ACWA’s 2024 Spring Conference & Expo May 7-9 in Sacramento are available below. […]

ACWA 2024 Spring Conference Committee Meeting Resources

Resources for ACWA Committee Meetings held during ACWA’s 2024 Spring Conference & Expo are available below.  Agriculture Committee Agenda Work […]

Regulatory Roundup

Sorry, but only ACWA members have permission to view this content. Member login is required.

ACWA Climate Change Policy Principles

Climate change impacts in California are occurring, with substantial further effects likely to emerge through this century. Climate change impacts […]

ACWA’s Infrastructure Bond Priorities

Adapting to climate change requires California to urgently and significantly rehabilitate and modify existing water facilities, improve operational flexibility, and […]

Coalition Letter: Proposed Rule for Principles, Requirements and Guidelines for Water Resources

To: Acting Director for Policy and Legislation, Office of the Assistant Secretary of the Army Subject: Agency Proposed Rule for Specific […]

2024 Water Awareness Month Toolkit

Sorry, but only ACWA members have permission to view this content. Member login is required.

Southern California Steelhead Status Review Submission to Commission

Agency: California Fish and Game Commission Subject: California Department of Fish and Wildlife Southern California Steelhead (Oncorhynchus mykiss) Status Review Submission […]

Proposed Making Conservation a California Way of Life Regulation Comment Letter

Agency: State Water Resources Control Board Subject: Comment Letter – Proposed Making Conservation a California Way of Life Regulation Letter excerpt: […]

Suggested News

15 Articles prev next
A Climate Resilience Bond must invest in California’s water future

The evidence is overwhelming. We are experiencing the impacts of climate change now. Our wet years are becoming warmer and […]

Bill That Would Have Banned Some New Groundwater Wells Fails to Pass Out of Senate Committee

AB 2079 (Bennett), which would have banned local agencies from permitting some new groundwater wells, failed to pass out of […]

Western Water Recognizes Local Youth Artists

RIVERSIDE – Western Municipal Water District (Western Water) recently celebrated the artistic talents of six students from Riverside County schools at […]

SCV Water to Begin Construction of New PFAS and VOC Treatment Project

As part of its commitment to restoring local groundwater reliability, SCV Water will soon begin construction of a new treatment […]

EBMUD Builds its Largest Solar Array

OAKLAND – Climate change affects every aspect of the East Bay Municipal Utility District’s work, from the resilience of our […]

Yuba Water Doubles Funding for Rescue Equipment and Training

MARYSVILLE – The Yuba Water Agency Board of Directors today approved increasing the maximum funding for rescue equipment and specialized […]

TUD Completes Critical Fuels Reduction Project

Tuolumne Utilities District (TUD) is pleased to announce the successful completion of the TUD Critical District Fuels Reduction (Phase 2) […]

Brad Koehn Appointed General Manager at TID

TURLOCK – The Turlock Irrigation District (TID) Board of Directors has appointed Brad Koehn as General Manager, effective June 21, […]

Groundbreaking Marks the Start of JCSD’s Recycled Water Project Construction

JURUPA VALLEY – A groundbreaking ceremony held by the Jurupa Community Services District (JCSD) marked the start of construction for the […]

June 2024 Priority Issues Update Now Available

The June 2024 Priority Issues Update is now available online to members. The update is a summary of the latest […]

Small Water System Support Yields Critical Improvements in Banning

BEAUMONT – In its latest gap funding effort, San Gorgonio Pass Water Agency (SGPWA) will aid High Valleys Water District […]

Littlerock Dam Celebrates 100th Anniversary

PALMDALE – With the serene blue water of the reservoir serving as the backdrop, nearly 100 dignitaries, community members and […]

Congresswoman Torres Presents Check to MVWD for Pipeline Replacement

MONTCLAIR – U.S. Representative Norma Torres (CA-35) presented a $959,757 check to Monte Vista Water District (MVWD) on Wednesday for […]

Federal Investment Funds California Surface Storage Projects

The Department of the Interior has announced a $242 million investment as part of President Joe Biden’s Investing in America […]

TID General Manager Michelle Reimers Announces Departure

TURLOCK – Turlock Irrigation District General Manager, Michelle Reimers, has announced her resignation effective June 21, 2024. Reimers has served […]