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Water Quality

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There are many reasons why water quality within the Pajaro Valley watershed is important.  Some of these reasons include:

  • Maintaining Pajaro Valley's agricultural heritage requires the availability of water that meets Regional Water Quality Control Board (RWQCB) standards.

Section 303(d) of the 1972 Federal Clean Water Act requires states to identify water bodies that do not meet water quality objectives and are not supporting their beneficial uses. 37 water bodies within the Central Coast are on the State's 303(d) list of impaired water bodies. As a result, Central Coast growers must utilize Best Management Practices (BMPs) to comply with water quality regulation by decreasing chemical and nutrient run off from their properties. Total Maximum Daily Loads (TMDLs) are evaluated by Regional Board Staff for impaired water bodies, and a plan for implementing the reduction of the pollutants is developed. In addition, farmers who apply water to irrigate their crops must comply with the Regional Water Board's Conditional Waiver.

For the Pajaro River Watershed, the following TMDLs have been completed by the Regional Board.

  1. Pajaro River (including Llagas Creek) Nitrate TMDL
  2. Pajaro River (including San Benito River, Llagas Creek and Rider Creek) Sediment TMDL
  3. Watsonville Slough Pathogens TMDL
  4. Clear Creek and Hernandez Reservoir Mercury TMDL
  5. Corralitos and Salsipuedes Creeks Watershed Fecal Coliform TMDL
  6. Pajaro River Watershed Fecal Coliform TMDL


Groundwater is the main source of water for residents and farmers in the Pajaro Valley, making groundwater quality very important to monitor. There are three coherent aquifers underlying the Pajaro Valley: the Alluvial, the Aromas, and the Purisma aquifers.

The Alluvial aquifer is most affected by agricultural run off and pollutants, because it is closest to the surface. Overdraft has caused seawater intrusion for all three aquifers and its effects are most pronounced in the Aromas aquifer (the middle ground water aquifer). The Purisma aquifer (the lowest) contains really old, mineral rich water that is not ideal for irrigation.

Pajaro Groundwater Aquifers 

Please go the PVWMA website for more detailed information on the hydrologic geology of the Pajaro Valley.

See the report prepared by the California Coastal Commission: California’s Critical Coastal Areas State of the CCAs Report June 2, 2006 for more information and links regarding water quality.

CCATF (Central Coast Agricultural Task Force) is dedicated to monitoring the issues that are most important to the livelihood of our central coast agricultural industry. They publish a weekly e-newsletter that  contains recent articles on water quality and other issues regarding agriculture.

Ag Waiver

US Congressman Sam Farr’s letter to the Central Coast Regional Water Quality Control Board regarding the Agricultural Waiver.

On March 2, 2011, Central Coast Water Board staff released recommendations for a revised Agricultural Order.  Staff’s recommendations (Draft Agricultural Order, Draft Monitoring and Reporting Program, and Staff Report including the Subsequent Environmental Impact Report for the Regulation of Waste Discharge from Irrigated Lands) are now available for public review.  The Central Coast Water Board held a public meeting on March 17, 2011 to consider staff’s recommendations.  See the public notice for more information.  Documents are available at the Central Coast Water Board site.