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We have generated a 2-Page Summary on Management of Santa Cruz Mid-County Groundwater Basin (.pdf)

The Department of Water Resources has put together some FAQs for the Act and the GSA formation. Those can be found here:

The following questions are specific to the Mid-County Region:

1) What are the Top 5 Points our community should know about Mid-County groundwater issues?

  • Our shared groundwater basin is in a state of overdraft with seawater contamination at our coastline. This condition is unsustainable and is a result of historically pumping out more water than can naturally be replenished by rainfall. 
  • In 2014, California passed landmark legislation, the Sustainable Groundwater Management Act, which (for the first time ever in California) requires statewide management of groundwater. Locally, this means that a Groundwater Sustainability Agency needs to be formed by 2017, a Groundwater Sustainability Plan needs to be adopted by 2020, and water use from the basin must be sustainable by 2040, eliminating threats of seawater intrusion and other adverse impacts.
  • We have to work together to manage the groundwater in the Mid-County region. Currently, four agencies (the City of Santa Cruz, County of Santa Cruz, Central Water District, and Soquel Creek Water District) have partnered together and have included private well representatives to address the state mandate of sustainably managing the basin to meet the deadline of 2040.
  • Solutions to addressing the overdraft condition in our basin will need to include a diverse set of projects, programs, and activities to be undertaken by all basin users. Exactly how and what are to be determined, but could likely include a combination of water conservation, supplemental supply and increased groundwater recharge.
  • Community input and participation is critical. We are proud that people in the mid-county region have been coming together and talking about groundwater issues and managing their water use more efficiently.  We will continue to seek input and active dialogue along the way.

2) How can I be involved in the process?

  • Community participation is vital to the development of the GSP. The first step is to review the content on the website and sign up for the newsletter.
  • Community meetings are held on a regular basis to provide information to the public and allow residents to ask questions and make suggestions. These are posted on the website and announced via the newsletter.
  • The Board of the Mid-County Groundwater Management Agency oversees the management of the basin. The Board  meets bi-monthly, and the public are invited to attend these meetings.

3) Why has it taken so long for this community to take serious action about the overdrafting of our aquifers?

  • Groundwater management has been getting a lot of attention recently, but efforts to understand local groundwater hydrology and reduce overpumping have been happening since the mid-1990s. With the new State law, there is now a better mechanism (structure and incentive) to develop effective cooperation between all the groups who use our groundwater.
  • The Soquel Creek Water District came together with Central Water District to develop the first groundwater management plan for the basin in1995.
  • SqCWD formed a community advisory committee in 1996 to develop an Integrated Resource Plan to address the overdraft. The primary recommendation from this effort was to develop a desalination plant.
  • Plans for the desal plant were pursued as  a joint effort with the City of Santa Cruz for  over   five years. The voters of Santa Cruz passed Measure P, which led the City of Santa Cruz to put the desalination project on hold indefinitely.  As a result, Soquel Creek Water District  began a new review of supplemental water supply options and Santa Cruz formed a Water Supply Advisory Committee (WSAC) to do the same.  The Soquel District board decided on advanced water purification for groundwater replenishment as their preferred option, while the WSAC recommended that the transfer of San Lorenzo river water to neighboring districts (Soquel and Scotts Valley) be the first priority.  While the two agencies are pursuing different supplemental supply options, they are not necessarily mutually exclusive.
  • Hydrologists’ reports have gradually lowered their estimates of what is a safe yield for this basin. Salt water intrusion was first identified in the early 1990s.
  • The Soquel Creek Water District, the largest user in the basin, reversed the trend of increasing pumping in 2003, and pumping levels have continued downward ever since.
  • People don’t like to be told that they should use less water, Because of our multi-year drought, we have a good opportunity to get everyone’s attention about the effects of even regular water use. Water users have responded to the drought and have discovered how much they can reasonably reduce their water use. Even without the drought, we will continue to have a major issue with our groundwater.

4) What does “sustainable yield” mean? Is it a constant amount?

  • “Yield” is the amount of water that can be pumped out of the ground. To be sustainable, this amount must be less than what the environment puts back into the ground, while allowing for enough seaward flow to maintain freshwater elevation and pressure against sea water intrusion.
  • Since we have overpumped from our aquifers for 30 years, we have to further reduce our pumping to make up for that deficit in order to bring our water levels  back into balance.
  • Aquifers are recharged by rain falling and gradually seeping into the groundwater. Seepage from streams can also contribute significant recharge. Our aquifers are not like an underground bowl or lake, but more like slow-running underground rivers moving south-east, towards the ocean and towards La Selva Beach.
  • If rainfall amounts were to lessen, or if sea levels were to rise, these conditions would need to be calculated into the possible sustainable yield of the basin.
  • If our basin had 9000 acre feet of rain fall as the projected average for the next 20 years, and we allow for underground movement of water to the ocean and towards South County, we might have 6200 AF of possible yield. Then, if we reduce that by 1200 AF for the next 20 years to make up for overpumping, we could figure that pumping 5000 AF per year would be sustainable, since that would keep the basin in balance as to supply and demand. If that resulted in continued sea water intrusion pumping would need to be further reduced.
  • Of course, to be fully sustainable, we should also figure in the health of the water itself, of the environment that is supported by our rainfall and streamflow, and of the economic and social health of the population that is supported by our basin.

5) What impact does a private well have on the basin?

  • A residential well owner in the hills of Soquel or Aptos probably uses less than half an acre foot of water per year – we estimate between 105,000 - 130,000 gallons. There are about 2,000 such parcels in our basin. So when you think of the combined result of rural residential pumping, it is significant – the gross amount pumped (before return flow) is under a sixth of all basin usage.
  • We all pump from the same groundwater. You could oversimplify and say we all are sticking straws into the water glass and sucking – it doesn’t matter if you are near the rim or in the middle of the glass.
  • The actions of individual well owners can have a cumulative impact. Together we have significantly reduced the amount of pumping in recent years.
  • In addition to rural residential properties, there are other private pumpers in our basin: schools (like Cabrillo), camps (like Kennolyn or Seventh Day Adventist Camp), Seascape Golf Course, and agricultural users (nurseries, vineyards, orchards and row crops.) These groups together use more water than the combined use of Central and Santa Cruz Water Districts from the basin.
  • Another factor we are exploring in more detail is the idea of return flow. This is the concept that septic systems leach water back into the ground – whether this reaches the main aquifers through our various Purisima layers is under study. The general idea is that about 50% of rural residential water use returns to groundwater.
  • Rural pumping can also draw water from the shallow aquifers that feed our streams, and pumping may reduce the amount of water available for steelhead and salmon.

6) Can the new Groundwater Agency tell landowners how much they can pump? Will they require metering of private wells?

  • The Agency cannot directly control how much people can pump. However, it must monitor the amounts of pumping, and it will probably set guidelines for different types of usage (residential, agricultural, schools, parks, golf courses.)
  • The State law exempts minimal residential users from having to meter their wells. Small water systems are required to meter their usage, and any larger private pumpers or non domestic users, such as farmers, camps, golf courses and Cabrillo, will have to report their water use to the Agency.
  • The Agency might also establish an assessment program based on the amount of groundwater extracted. This would help to fund groundwater management projects, and would also help to provide incentives to reduce excessive pumping.

7) What are the possible solutions to our groundwater overdraft?

  • Santa Cruz County has done a great job with conservation – we are among the top cities and counties in the state in the percentage reduction in our water usage. We need to keep conserving, but we know the urgency in people’s minds will wane if we get some decent rainfall. Our problem in mid-county won’t go away with having regular or even increased rain, and conservation isn’t enough to fix our problem.
  • The Soquel Creek Water District board has prioritized further research on replenishing the aquifer by injecting purified waste water to help to slow the spread of salt water intrusion near the coast.
  • The City of Santa Cruz Water Supply Advisory Committee has recommended water transfers during the winter months, from their extra water in the San Lorenzo River to Soquel Creek, which would help to reduce the pumping by the Soquel Creek Water District. They will also investigate the feasibility of injecting some of that extra water into the aquifer. (The idea is that this extra stored water could be drawn on by Santa Cruz Water when they need extra in the future – in summer drought conditions.)
  • There is work being done to develop a desalination plant in Moss Landing by a private group.  If this becomes a viable and cost-effective option, it could potentially supply additional water to the region.
  • Local agencies are also exploring options to capture stormwater from parking lots and urban areas, filter it and put it back into the ground to increase recharge.

Have a question?  Email Sierra Ryan at and we will add your questions to this list