What do Multiple Benefits Look Like in a Watershed?

By Jenny Baker, Senior Restoration Manager, and Heather Cole, Puget Sound Community Relations Manager

Multiple benefits are a core feature of finding solutions that work for all the different interests in a watershed. Multiple benefits in a floodplain context means finding workable solutions that restore habitat, reduce flood risk, support farmers and meet other community needs. But what does that look like in practice?

In mid-July we convened floodplain managers, tribal representatives and farmers to learn from each other and to share practices from the Skagit and the Nooksack watersheds. The focus of the tour was to better understand agricultural needs and how to incorporate those into community conversations around floodplain management. We met with commissioners from Skagit’s Dike District 22 and Dike District 3, a project manager from the Skagit Drainage and Irrigation District Consortium, the executive director of Western Washington Agricultural Association, and Whatcom Conservation District staff to learn about sites where the needs of farmers were included in projects.

In mid-July we convened floodplain managers, tribal representatives and farmers to learn from each other and to share practices from the Skagit and the Nooksack watersheds. © Jenny Baker / TNC

A big issue for agriculture is managing water. As you hear from Puyallup farmer Ivan Matlock in this video, “If you don’t have enough water at the right time, you go broke. If you get too much water at the wrong time, it damages your land and your crops — you also go broke.” It takes a coordinated and well-designed system to manage water for agriculture — and a number of ideas are being tried around Puget Sound as part of multiple-benefit efforts. Pumps, dikes and levees, fish-friendly flood- and tidegates, drainage storage capacity, agricultural easements and vegetation management along ditches were some of the on-the-ground features we looked at and talked about on the tour.

At Fir Island Farm in the Skagit delta, a drainage storage pond and a pump were added to offset impacts from habitat restoration and to provide more certainty of drainage capacity as sea level rises. The old dike that often overtopped was replaced with a setback dike that is taller and better designed to protect the farmland behind it. And some failing tidegates that carry water from the farmland out to the bay were replaced with new ones.

new fish-friendly floodgates at Fisher Slough which maintain flood protection while improving fish passage and tidal exchange onto the restoration site. © Jenny Baker / TNC

At Fisher Slough in the Skagit delta, a large pipe in need of repair was replaced with a modern structure that is designed to provide better drainage, the installation of fish-friendly floodgates maintained the function of a critical flood-control structure, a new setback levee was better designed to protect the farmland behind it, and a farmland easement on nearby property was purchased to partially offset the loss of farmland that was restored to estuary.

inlet to a new inverted siphon at Fisher Slough, part of updated drainage infrastructure completed as part of project construction. © Jenny Baker / TNC

At the hedgerow sites in the Nooksack watershed, we saw narrow, dense plantings along streams and ditches. The hedgerows were planted to shade out grasses that were growing in and along waterways and causing sediment to be trapped and the water to back up. After 10 years, dense thickets of Pacific ninebark, red osier dogwood, twinberry and nootka rose shade these waterways, completely eliminating the need for dredging or spraying grass with herbicide. In addition, research is showing that water temperature is reduced and “drift” from aerial pesticide applications is reduced in waterways with hedgerows.

At the hedgerow sites in the Nooksack watershed, we saw narrow, dense plantings along streams and ditches. Photo © Jenny Baker / TNC

We had good discussions about how these techniques may work in some places and may not work in others. But having as many "tools in our toolbox” to find workable local solutions was the common denominator for the group.

There’s no magic bullet or a one-size-fits-all solution when you’re talking about multiple benefits. But as we learned on the tour, understanding the needs of the farmers who live and work in the floodplain and the water management systems they depend on are part of finding workable solutions that keeps farms, salmon and people on the landscape.

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