Nearly all of Santa Cruz County's domestic water supply is derived from local surface water (streams and reservoirs - 20% of supply) and groundwater (80% of supply), which are fed entirely by precipitation and do not receive any imported water. Partially because Santa Cruz County obtains all its own water it is somewhat insulated from drought that has a greater impact on the portions of the state that rely on State or Federal water projects for their supply. However, the County continues to face major water supply challenges in that most groundwater basins have more water removed on an annual basis than is replaced and the major water supply agencies do not have sufficient sustainable supplies to meet current and future demand, even with very effective water conservation programs already in place.
The San Lorenzo Valley Water District (SLVWD), Scotts Valley Water District, City of Santa Cruz Water Department (CSCWD), Soquel Creek Water District, Central Water District (CWD), City of Watsonville Department of Public Works and Utilities and the Pajaro Valley Water Management Agency (PVWMA) are the major water agencies in the county. Except for the recycled water project, the PVWMA does not provide water but rather is a management agency tasked with developing supplemental supplies and bringing the aquifers within its boundary into sustainable yield.
The major water purveyors share the water resources in the county and most purveys obtain water from multiple sources. While most of the major purveyors depend solely on groundwater for their potable supply, the CSCWD, CWWD and SLVWD get a large portion of their water supply from local streams. The CSCWD is the largest user of surface water in the county, deriving approximately 90% of their supply from the San Lorenzo River Watershed and North Coast streams. The water purveyors are working together to make our limited water resources sustainable for current and future generations of Santa Cruz residents.
Outside of the municipal service areas, individual parcels and communities rely on private wells and stream diversions for their water supply. Santa Cruz County, acting as a Local Primacy Agency for the State Water Resources Control Board, oversees small water systems serving between 5 and 199 water connections. The Small Water System Regulatory Program is designed to ensure that small public water supply systems deliver a reliable and adequate supply of groundwater or surface water to their customers. There are approximately 130 small water systems in the county serving roughly 2,500 households. Additionally, there are at least 8,000 private wells in Santa Cruz County that serve between 1 and 4 households.