1999 - Salinas River Watershed Management Action Plan, Central Coast Regional Water Quality Control Board
To more effectively protect and improve water resources, the Action Plan attempts to develop local solutions to local problems. Many significant identified water quality impacts in the Salinas River Watershed, such as erosion and sedimentation, nitrates in the groundwater and surface water, and older, discontinued pesticides in sediments and animal tissues, are primarily associated with nonpoint pollution sources. Also, widespread groundwater pumping contributes significantly to seawater intrusion into the coastal aquifers. The Action Plan approach includes: 1. devoting additional Regional Board resources to watershed activities, 2. increasing the Regional Board presence by developing partnerships with landowners, local governments, resource agencies and other stakeholders, 3. integrating existing Regional Board programs, and 4. improving internal communication and coordination to increase efficiency and provide better service to point source dischargers and others in the watershed.
1999 - Water Resources and Land Use Change in Salinas Valley, Watershed Institute Report No. WI-1999-01
The 1999 report prepared by Fred Watson, Lars Pierce, Mel Mulitsch, Wendi Newman, Adrian Rocha, Mark Fain and Jodiah Nelson of the Watershed Institute, describes the progress made toward the use of computer modeling to provide both understanding and predictive capability. The Salinas River watershed of over 11,000 square kilometers supports large areas of intensive agriculture production, including large areas of intensive crop production, and extensive cattle ranches supporting annual grasslands. Mainly a dry climate with limited surface water resources, the valley has a finite groundwater system. Agriculture accounts for 93.5% of the groundwater extractions that exceed recharge by 40,000-50,000 acre feet per year (1999). Also, Nitrate fertilizer has contaminated the groundwater. Lower groundwater levels have allowed seawater to intrude several miles inland. The use of computer modeling provides the ability to predict the hydrological and ecological impacts of land use change, facilitates better-informed planning, detrimental changes can be avoided, and beneficial changes can be promoted.
2000 - A Line Through the Past – Historical and Ethnographic Background for the Branch Canal, California State Water Project, Coastal Branch Series Paper Number 1.
This 2000 publication of the San Luis Obispo County Archaeological Society documents the major prehistoric and historic studies carried out in connection with the California State Water Project, Coastal Branch, Phase II. The State Water Project delivers water from the California Aqueduct to San Luis Obispo and Santa Barbara counties. The California Department of Parks and Recreation along with various cultural resource management firms, conducted the cultural resources studies and reports for the State Water Project.
2003, April – Land Use History and Mapping in California’s Central Coast Region; Report No. WI-2003-03; Newman, W. B, Watson, F.G.R,
Land use change has a long history in the region, which once held the State Capitol at Monterey. The region been transformed several times, following the introduction of Europeans and their grain crops in the 1800s, the development of groundwater-based irrigation in the late 1920s, and the expansion of vineyards and urban areas in more recent years.
Land management must be aware of the history of the land, and of its current spatial state. The early chapters of this report review the major land use systems of the region and their history. The latter chapter presents a new remotely sensed land use map of the region. The report was prepared within the context of sediment source analyses (Watson et al., 2003). Reference is made to erosion from certain land types where appropriate.
2013-2014, August - Integrated Regional Water Management Plan for the Greater Monterey County Region
An Integrated Regional Water Management Plan (IRWM Plan) developed by 18 member entities that include government agencies, nonprofit organizations, educational organizations, water service districts, private water companies, and organizations representing agricultural, environmental, and community interests. The IRWM Plan is an expansion and modification of a previous plan – the May 2006 Salinas Valley Integrated Regional Water Management Functionally Equivalent Plan developed by Monterey County Water Resources Agency. While the traditional approach to water resource management has typically involved separate and distinct agencies managing different aspects of the water system, i.e., water supply, water quality, flood management, and natural resources, integrated regional water management considers the hydrologic system as a whole. The IRWM planning process brings together water and natural resource managers, along with other community stakeholders, to collaboratively plan for and ensure the region’s continued water supply reliability, improved water quality, flood management, and healthy functioning ecosystems—allowing for creative new solutions, greater efficiencies, and an increased promise of long-term success.
2013, August 7 – California State Water Resources Control Board ORDER WR 2013-0030-EXEC and June 2013 Settlement Agreement with Monterey County Water Resources Agency
Monterey County Water Resources Agency (formerly Monterey County Flood Control and Water Conservation District) submitted Application 13225 and 13226 (combined into Permit 11043) in response to problems of seawater intrusion in the Salinas Valley Groundwater Basin examined by California Department of Public Works in Bulletin 52 published in 1946. The express intent of the application was to implement the solutions outlined in Bulletin 52 to combat sweater intrusion by diverting 400 cubic feet water per second from Salinas River for municipal and agricultural uses, not to exceed 168,538 acre-feet per year.. Phase I was successfully implemented in 2010. Phase II had yet to be implemented. A hearing on the proposed revocation of Permit 11043 was set for August 13, 2013. A settlement agreement between the California State Water Resources Control Board and the Monterey County Water Resources Agency was entered into in June 2013 that provided amendments to Permit 11043 and established milestone for the implementation of Phase II of the Salinas Valley Water Project.
2013, November 19 - Protective Elevations to Control Sea Water Intrusion in the Salinas Valley, Geoscience for MCWRA
A report prepared in support of preventing revocation of Permit 1043 (State of California Division of Water Rights Permit for Diversion of Use of Water – Amended Permit 11043 dated 110-Jul-49) that allows for appropriation of water from the Salinas River in Monterey County California not to exceed 400 cfs with annual maximum diversion not to exceed 168,538 acre feet per year. The report addresses the potential beneficial uses of diverting water to help increase groundwater levels in the Pressure and East Side Subareas that would in turn help to control seawater intrusion.
Discussion of the historically low groundwater levels in the Salinas Valley, noting that the shallower wells have become unreliable. As the groundwater levels drop below sea level, the seawater intrusion in the coastal aquifers will worsen. Because of the fast-declining groundwater levels on the east side of the Salinas Valley, the potential for seawater moving inland increases. Enhancing recharge in these areas would be beneficial in reducing seawater intrusion while lowering flood risk and erosion damage. The article reviews potential strategies to increase infiltration of rainwater during winter storms thereby recharging the underlying aquifer.
2015 – Project Justification – Addressing an Urgent Water Supply Need for a Disadvantaged Community in the Greater Monterey County IRWM Region
One hundred percent of Castroville’s water supply comes from the 400-foot aquifer of the Pressure sub-basin of the Salinas Valley Groundwater Basin. Groundwater levels in the aquifer dropped more than 100 feet below the seal level as of July 2015 at static conditions. Water levels dropped to more than 190 feet below the mean sea level during operation of the water well. The dramatic drop combined with the close proximity of the Pacific Ocean (less than 4 miles) and to existing seawater intrusion (less than ¼ mile) raised significant alarm that the existing water supply system to Castroville was imminently threatened with high salinity water. The water supply was likely to be contaminated within the year. The project addressed the needs by (a) drilling a new water well in the Deep Aquifer that would supply Castroville with 500 AFY of potable water, (b) installing water filtration for arsenic and other contaminants, (c) installing a 600,000-gallon water holding tank, and (d) implementing water conservation activities to reduce water consumption and raise community awareness.
2015 - Salinas River Watershed Area Salt Modeling Assessment Prepared for California Central Coast Regional Water Quality Control Board and the U.S. Environmental Protection Agency, Region IX
A November 2015 report prepared by Tetra Tech for California Central Coast Regional Water Quality Control Board and the U.S. Environmental Protection Agency, Region IX. The purpose was for the informed development of salt-related TMDLs by the CCRWQCB and a salt and nutrient management plan for the Salinas Valley aquifers. Three reaches reported 2010 303(d) listings for salt-related impairments in these watersheds including impairments due to chloride, sodium, electrical conductivity, and total dissolved solids – Lower Salinas River, Santa Rita Creek, and Alisal Creek. This report provides data analysis and a literature review (Sections 1 through 5), development of a water and salt mass balance tool (Sections 6 through 8), and salt source assessment (Section 9). The results of the analysis would provide a strong foundation for assessing salt sources and understanding salt mass balance in the study area, but can be improved with refined representation of cropland locations, rotations, and irrigation practices.