Water District Plans to Siphon Groundwater From Ojai Mountains

A cross-section view of the proposed horizontal bore from CMWD’s proposal analysis. Click to enlarge.

Late last year, Casitas Municipal Water District (CMWD) approved a plan to explore the use of large horizontal bores that would siphon groundwater from underneath the Los Padres National Forest and into Lake Casitas. The bores would be drilled from CMWD property outside of the national forest boundary and extend horizontally beneath national forest land. Water stored in the Matilija sandstone, a source of groundwater below White Ledge Peak and the surrounding area, would naturally flow into the horizontal bore and travel all the way to Lake Casitas, the primary source of drinking water for the Ojai area. ForestWatch submitted a letter detailing some concerns about the plan to CMWD back in January.

The bores would only siphon water from the Los Padres National Forest during long-term droughts, according to the Preliminary Water Security Project Analysis published by CMWD in November of last year. In that analysis, the “Matilija Formation Horizontal Bores” plan was listed as the preferred option out of six alternatives. Of the six alternatives, the horizontal bore project was the second most expensive proposal at $5.5 million.

You can read the Preliminary Water Security Project Analysis here.

In our letter to CMWD, we discussed the potential impact the horizontal bores could have on surface water in the Los Padres National Forest. Groundwater supplies natural springs and streams such as Matilija Creek, which supports habitat for the endangered arroyo toad and many other rare species that make the Los Padres National Forest so unique. Any depletion of groundwater could have an impact on surface water supply and subsequently limit the amount of water available for plants and animals that rely on these streams and springs. Additionally, mining water from beneath the Los Padres during drought years – when water levels are already at critically low levels – would place additional strains on the forest during prolonged dry spells.

We also highlighted the need for the project to go through permitting and environmental review, a process that would place a burden on the Forest Service which is already facing budget shortfalls. We also highlighted the need to explore alternative proposals that are not only less expensive but are also environmentally-preferable. We also found that a substantial amount of water could be produced by combining several proposed projects for a total of only $2.7 million. These projects would include retrofitting, repairing, and replacing existing infrastructure rather than building new infrastructure that could impact the Los Padres National Forest.

We will provide an update after CMWD responds to our letter and lets us know how they will address our concerns. Check out the map below to see where exactly horizontal bores could be drilled beneath the national forest.

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