Update on 2021 Water Shortage in Santa Cruz County
In our New Tech event on September 3, 2021, Rosemary Menard gave a brief overview of the current water supply situation and actions being pursued to address Santa Cruz’s long standing water supply reliability issues. Topics covered included the work the Water Department is doing on how climate change is affecting water supply reliability and how the various water supply augmentation options that are under review. Rosemary is Santa Cruz’s Water Director and Interim City Manager.
Key Takeaways
Loch Lomond Reservoir is 23 feet below full.
Daily demand is ~7.5 million gallons; leaving 30% of customers struggling to stay within their allocation.
Vulnerability to drought is caused by several drivers:
Limited storage is the most significant, and cannot be solved by conservation alone.
Increasing supply variability associated with climate change
Fish flow requirements
Limited availability of groundwater due to threat of seawater intrusion into the aquifer
2021 is a one of the top 4 critically dry years over the span of 100 years.
2022 is forecasted to be another dry year.
Supply augmentation is underway with project implementation due in 2022 including
Aquifer storage and recovery (ASR) in either/both
Santa Cruz mid-county - least expensive solution due to existing infrastructure.
or Santa Margarita groundwater basins; most expensive.
Indirect potable reuse (IPR) of advanced treated recycle water with torage in local groundwater basins
State and Federal infrastructure funding being pursued.
If 2022 is another critically dry year, groundwater can aid us. Groundwater resources are more resilient to drought because impact from drought takes much longer, though recovery takes longer too.
Desalination is the most expensive, does not require storage. It maybe reconsidered as a long term solution depending on many other factors.
The Santa Cruz community has continued to conserve water since the 2014-15 droughts. Keep it up!
Water supply and the urgent need for affordable housing are not contradictory. The issue in Santa Cruz is supply variability, it is NOT demand. The water demand is projected to grow 16% over the next 25 years. The supply variability under best and worse case scenario is 225%. Putting off affordable housing does not change size of the supply issue.
