Water Neutral Growth

Growth Increases Our Drought Risk

Santa Cruz needs water policies that will allow reasonable growth to continue without increasing demand for water.That way we can effectively manage our drought risk. A 2004 City Water Department report(1) put it this way:

“Continuing to provide water to new customers upon request, as is the current practice, may do harm to existing customers by making the potential water shortage situation worse than it would otherwise be.”

The report describes why growth worsens the impact of droughts:

“It is important to note that, even in normal water conditions, three of the four major sources [North Coast streams, San Lorenzo River, Live Oak wells, and Loch Lomond] are presently being utilized at maximum capacity for a significant portion of the year…What this means operationally is that any future increase in seasonal or annual demand for water will be felt through greater and greater withdrawals from Loch Lomond reservoir.”

The Draft Environmental Impact Report for the desal project quantifies the sizable impact that growth has on increasing the shortfall the City would experience during a worst-case drought. Although the numbers in the estimate need revision, according to the California Department of Fish & Wildlife2, the estimates reveal that an increase in net water demand of just 9% by 2030 could increase the shortfall dramatically (from the current 29% to 37%). When a system reaches the limits of its capacity, an additional strain will have an outsized impact—as in the metaphor of the straw that broke the camel’s back.

We Can Grow Without Using More Water

Water-neutral growth allows new development without increasing the total water demand on the system. Water-neutral growth is achieved by implementing a water demand offset program, where developers fund conservation retrofits elsewhere in the system to offset the new demand for water created by the development.

A water-demand offset program for new development encourages developers to build new buildings that are highly efficient. Developers can reduce their offset fees when they dem­onstrate that a building would use less water than current code requirements would other­wise indicate.

This is already working nearby. Inspired by early efforts by East Bay Municipal Utilities and San Luis Obispo County, Soquel Creek Water District has operated a water demand offset program since 2003. This program is an important factor contributing to Soquel’s projection of a net decline in water demand of 7% by 20303. In contrast, Santa Cruz antici­pates a net increase in water demand of 9% by 20304.

Our County’s Local Agency Formation Commission (LAFCO) adopted a water neutral policy:

“In cases where a basin is overdrafted or existing services are not sustainable, a boundary change proposal may be approved if there will be a net decrease in impacts on water resources.”

This provision impacted the application to LAFCO by UCSC and the City of Santa Cruz for water service extension to develop the university’s upper campus. Initially the City argued that the decline in water consumption during the previous ten years in spite of urban growth was evidence that it had effective water neutral policies. However, this was contradicted by the City’s Water Supply Assessment, which projected that future growth in demand that would outstrip conservation measures. Subsequently, the City proposed that increased water demand at UCSC would be offset by washing machine rebates in town. That’s the kind of approach we need—not just for campus growth, but also for growth in the entire water service area.

Drought Security Comes First

A legitimate question about Soquel Creek’s water demand offset program has been, “The District is using the most cost-effective conservation measure (toilet replacement) to off­set growth. Shouldn’t the District use the most cost-effective measures to reduce existing water demand on the overdrafted system—and let developers pay for other measures to offset their growth?”

Conservation measures are finite. Once toilets are replaced throughout the District, that measure is exhausted. The question is whether to allow developers to use up the cheap­est ways to reduce water demand at a time when the District desperately needs to reduce groundwater pumping for existing users.

Similarly, Santa Cruz faces a choice between allocating conservation measures to offset growth, or to improve drought security for existing customers. If conservation measures are primarily allocated to offset growth, that will not improve the City’s shortfall during drought.

We argue that drought security for existing users ought to be a top priority of City con­servation programs. Every measure that reduces water demand of existing users means more water stored in Loch Lomond in case of drought. When water demand is on track to achieve the reduced level that the community decides is adequate for drought security, our community can afford to commit water for development. If and when new water supplies come online, this prioritization can be revised.

Prioritizing conservation measures to reduce drought curtailment means that in creating a new Conservation Plan, the community would make a decision about which conservation measures go towards water security for existing customers and which measures would be funded by developers in a water demand offset program.

In summary, a reasonable approach to providing for growth is for those who will profit from growth (developers) to pay for the conservation measures that will allow the city to provide them with water without having to increase our overall supplies.


1. Adequacy of Municipal Water Supplies to Support Future Development, Santa Cruz Water Department report, 2004.

2. CDF&W comment on the desal dEIR: “Although the City has since updated the Tier 2/3 data set and modi­fied rule curves for its discussion with the Agencies, it does not appear that the corrected data input files and Confluence™ model assumptions were used for the Appendix C Technical Memorandum analysis provided in the draft EIR. As such, it is unlikely that the information provided is accurate and CDFW recommends that the Technical Memorandum be revised to reflect the most recent flow proposals and modeling efforts. Without an accurate representation of the effects of the different flow proposals on the City’s water supply, the analysis provided in the draft EIR may not be sufficient to support statements that the bypass flows in the HCP will have a signifi­cant impact on the City’s water supply or that alternative infrastructure improvements are not sufficient to provide water reliability.” (dEIR Table 3-10)

3. Soquel Creek Water District, Integrated Resources Plan Update (2012), Table 4-4 shows an estimated growth in water demand of 9% by 2030 from the baseline year of 2015. After conservation, the water demand declines by 7%.

4. Santa Cruz’s Urban Water Management Plan estimates growth in water demand of 500 million gallons per year or 14% by 2030. The Draft EIR for the Desal Project (2013) estimates conservation programs reducing demand by 200 million gallons by 2030. Hence there is a net increase in demand of 9% by 2030

This entry was posted in Uncategorized. Bookmark the permalink.

One Response to Water Neutral Growth

  1. Rich Persoff says:

    Questions about supplying water to any new construction:

    How many gallons per year will the new building require?

    How much of these needs could be met by collecting and storing rainwater from buildings on-site?

    Could these needs be eliminated by composting toilets and on-site water purification for reuse? Yes, this costs more than piped water, but there’s room for cost-shifting on any project!

    Would this project be viable if not supplied with piped water AND had no well?

    If a project can’t exist unless connected to our overdrafted groundwater and reservoirs, it shouldn’t…

Leave a Reply

Your email address will not be published. Required fields are marked *

 characters available

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>