Sanctuary Forest

December 10, 2007


Sanctuary Forest's Mattole Flow Program continues to lead the way for our community and the land trust movement in the area of rural water conservation and protection of instream flows. The goal of the Mattole Flow Program is to maintain healthy instream flows for fish and people during the critical dry season. Since 2000 the Mattole watershed and many other north coast rivers have experienced a prolonged pattern of extreme low stream flows threatening the survival of endangered salmonids and the water supply of rural communities.

Monitoring in-stream flow Photo: Sanctuary Forest archives

This summer the Mattole Flow Program reached a major milestone with installation of the first two of what will be a total of eighteen large capacity water storage tanks installed in the Mattole headwaters. Participating landowners who receive these tanks enter into binding long term legal agreements not to pump from the river during the critical low flow season. Participants use the stored water instead, maintaining water in the river when fish need it the most. This program of "storage and forbearance" addresses the fact that human use accounts for 20-80% of the headwater's flows depending on the severity of the dry season. Through installation of these tanks Sanctuary Forest expects to make significant improvements to summer flows in two critical salmon habitat reaches of the river that now normally run dry.

Monitoring the river's flow and continuing to study the causes, effects and potential solutions to the low flow crisis are important aspects of the Mattole Flow Program. Two such studies initiated this past spring and summer included a salmon survival study and a ground water monitoring study.

Despite the obvious connection there is little scientific literature on the survival of salmon under low flow conditions. For this reason Sanctuary Forest initiated a fish survival study in collaboration with UC Berkeley graduate student Ted Grantham and the Mattole Salmon Group. This study made repeated population counts of fish throughout the dry season, documenting mortality under various habitat conditions. Up until now we could only speculate on how many fish are lost because of the low flows. Through continuation of this study we hope to demonstrate the ongoing need and effectiveness of the Mattole Flow Program in restoration of native salmon.

Sanctuary Forest has been monitoring stream flows in the Mattole headwaters each summer season since 2004. What`s new for 2007 was the beginning of our program to monitor the flows of groundwater. Like the relationship between a tree and its roots, you cannot understand a river without studying what happens to the vast amount of water stored underground in soil and rock. Preliminary ground water monitoring indicates ground and surface water in the Mattole are very connected and that summer instream flows are highly dependent on the flow of ground water. For this reason

Sanctuary Forest is preparing a ground water management plan for the Mattole River headwaters and studying the potential to help increase summer flows through ground water recharge projects.
Sanctuary Forest recognizes the importance of water to maintaining the health of our forest ecosystem. Through the Mattole Flow Program we are making significant strides in addressing our own low flow problem as well as developing innovative tools that other communities and land trusts can use in addressing the widespread need for water conservation.

In recognition of Sanctuary Forest's innovations as a land trust working in the area of water conservation, we were invited to make presentations about the Mattole Flow Program to the California Council of Land Trusts and the National Land Trust Alliance Rally.

For more information: www.sanctuaryforest.org


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