Restoring Watershed Processes in the Salinas Valley

The goal of the Multi-benefit Land Repurposing Program (MLRP), as described in the previous post, is to construct water resource projects that make Salinas Valley farms, communities, and the environment  more resilient and sustainable in the face of climate change. One of the ways we’re working to achieve this goal is by developing projects that restore natural watershed processes that have been lost to agriculture and urbanization. 

Before the Salinas Valley became the highly productive agricultural region it is today, earning the moniker ‘Salad Bowl of the Nation’, the northern end of the Salinas Valley was full of freshwater lakes stretching from Castroville eastward beyond the City of Salinas. These lakes filled with runoff from the Gabilan mountains and northern valley, creating valuable freshwater habitat and a water source for early 20th century communities and agriculture. Over time, as the valley was electrified and farmland became more valuable, these lakes were pumped dry to ‘reclaim’ these lands for farming. Today only a small fraction of the area once covered by lakes still remains.

Hand drawn map of freshwater lakes (green) extending eastward (left to right) from Castroville to the City of Salinas. This map was included in a report to the Monterey County Board of Supervisors on October 20th, 1910.

These historic lakes still flood during winter storms but are then pumped dry quickly to allow farming later in the spring. This management strategy does not allow for watershed processes that help reduce flooding, recharge aquifers, eliminate pollutants and support aquatic habitat. If small portions of these historical lakes were restored, they could once again provide the benefits of watershed processes that existed in the early 1900s. These processes are all the more important today, with larger storms caused by atmospheric rivers, more impervious surfaces generating stormwater runoff (like urban development and strawberry farms), and more densely populated areas vulnerable to flooding. 

If we were to allow for the capture of runoff from large rain events, we could mitigate flooding experienced by downstream communities. Storing this water during the rainy season would result in a new water source available for use during the hot, dry season when demand is higher. This would, in turn, reduce the strain on groundwater. 

Flooded farmland on the edge of the remaining Espinosa freshwater lake in the Salinas Valley. If this small, flood-prone area of farmland were restored and added to the footprint of the lake, it would increase the storage capacity of the lake and reduce downstream flooding. Drone imagery, January 2023.

So what does this have to do with the Multi-benefit Land Repurposing Program? Interestingly, or perhaps unsurprisingly, many of the agricultural landowners who have shown interest in MLRP, are considering selling acreage within the footprint of these historical lakes.

The flood-prone nature of these low-lying areas makes them less desirable for farming, particularly as we experience more intense storms that generate large amounts of rain in a short period of time. These flood areas are the most difficult and expensive areas to farm, making them perfect for MLRP, a program focused on transitioning low productivity farm land back to aquatic habitat, achieving environmental, agricultural, and economic win-win-win solutions.

Through MLRP, a lakebed restoration can compensate farmers for land they no longer want to farm, improve the resilience of our water supply, reduce downstream flooding, and provide freshwater habitat that used to exist in abundance.