By Monserrat Solis, SJV Water
A state water quality agency hopes to tackle a problem as old as civilization itself – salt build up from irrigation.
The Central Valley Salinity Alternatives for Long-Term Sustainability (CV-SALTS) is working with local water managers and using state-of-the-art engineering software to understand how groundwater moves through the western Kings and Delta-Mendota subbasins as part of a long-term salt study.
The salt study, which began in 2022, aims to develop a Central Valley-wide plan to manage salinity, focusing first on the Kings and Delta-Mendota subbasins.
“We’re looking at planning horizons of 50 to 100 years or more to assess how the valley will be changing in terms of salt accumulation, how it changes over time and depending on where you are in the valley,” Tom Grovhoug, an engineering consultant for the Central Valley Salinity Coalition said during a June 30 CV-SALTS webinar.
The salt study is still laying the groundwork to understand the complex San Joaquin Valley watershed and aquifer system. CV-SALTS will begin developing water and salt management plans by 2026 and develop a prioritization plan by 2028.
“The goal of the study is to come up with solutions, which are protective of irrigated agriculture, municipal drinking water and other uses,” Grovhoug said.
The salt study is funded by CV-SALTS’ finance arm, the Central Valley Salinity Coalition, which is made up of public agencies, businesses and farm groups. The coalition is tasked with raising $1.5 million or more annually for the next ten years to pay for the salt study.
Salt discharge can come from wastewater treatment plants, agricultural drainage, irrigated farmland and food processing plants. Those salt dischargers pay a fee that funds that will be used to help fund the salt study. More than 850 entities have paid fees towards the salt study as of November 2021.
The salt study will also look at salinity in relation to ground and surface water management.
“I mentioned water because we’re not just approaching the study as a salt issue. It’s really a water management issue,” Grovhoug said.
Participation by groundwater sustainability agencies (GSAs), irrigation districts and municipalities is key to obtaining the representation of each subbasin in the software being used, he said.
“The key information that we’ve gained from stakeholders is with regard to water management, irrigation practices, how and when surface water and groundwater are used, which is very important,” Grovhoug said.
Groundwater plans now being implemented under the Sustainable Groundwater Management Act (SGMA) likely will be impacted by results of the salt study.
Some groundwater plans already include land management and recharge projects to address salinity and other water quality issues, Grovhoug said.
Those plans and projects will be adopted into the salt study’s model to test their effectiveness, he said.
The salt study is the first phase of a larger plan, the Salt Program, to address the significant impact of salts in Central Valley soil, groundwater and surface water.
Phase two and three will focus on designing, permitting and constructing management projects for problem areas identified in the study.
Salt buildup in soils has been a significant problem since irrigation began thousands of years ago in the “fertile crescent” of what is now the Middle East. Poor drainage led to salt build up, damaged soil, failed crops and, eventually, abandonment of entire cities.
The pattern has repeated itself in modern times here in California. The giant Westlands Water District, in western Fresno County had to permanently retire nearly 100,000 acres due to salt build up.
