IMW Plan 2004: Evaluating Watershed Response to Land Management and Restoration Actions: Intensively Monitored Watersheds (IMW) Progress Report

Millions of dollars have been dedicated to the restoration of freshwater habitat since the listing of many populations of salmon in the Pacific Northwest in the 1990s. Little is known about the efficacy of these efforts. The most effective means of determining the contribution of restoration projects to salmon recovery is to implement experimental, watershed-scale evaluations. This document describes a series of intensively monitored watersheds (IMW) being established in Washington expressly to measure the effect of habitat restoration on salmon and trout productivity.

The IMW effort in western Washington is split between three sets of smaller, paired watersheds (complexes) focusing on coho salmon, and steelhead and cutthroat trout and the Skagit River estuary focused on ocean type chinook. The sole eastern Washington IMW is a BPA-funded effort on the Wenatchee River being coordinated by NOAA Fisheries. Restoration and monitoring objectives vary among the IMWs according to current condition, land use, and restoration potential and are described in the document.

The basic premise of the IMW project is that the complex relationships controlling salmon response to habitat conditions can best be understood by concentrating monitoring and research efforts at a few locations. We have begun implementing a monitoring framework that includes water quantity, water quality, habitat, summer juvenile fish abundance, and smolt production and are identifying specific restoration actions for the purpose of better understanding how salmon and trout respond to current approaches to restore habitat.

We are developing a landscape classification approach with NOAA Fisheries that will aid in applying the information (regarding fish response to habitat restoration) gained from these IMW complexes to more efficiently directing salmon restoration efforts across the state. We have ranked watersheds statewide according to the potential use as IMWs. Ranking criteria included: the feasibility of obtaining quantitative estimates of smolt production, the record of smolt monitoring, fish species present, and influence of hatchery-produced fish. This list may be used to direct other IMW efforts as needed.