Nisqually Delta Restoration


The Nisqually River begins in the glaciers of Mount Rainier and rushes 78 miles to its mouth on the shores of Puget Sound. The Nisqually estuary is protected by the Nisqually National Wildlife Refuge, and is one of the largest contributors of freshwater to the South Puget Sound ecosystem.

The intact estuary was not always guaranteed, however. In the late 1800s, the river delta was diked to create fertile farm land. This effectively blocked saltwater from entering the river delta, and created a freshwater ecosystem instead. Grasses and other plants took over. Other plans for the delta included installing a deep water port, or building a dump. Luckily, area residents and community leaders recognized the unique habitat of the delta, and pushed for conservation. In the 1970s, it was declared a national wildlife refuge!

Although the land was now under protection, the dikes remained in place, forming a different habitat than was historically in place. After more than a century of diking off tidal flow, the Nisqually Indian Tribe, Nisqually National Wildlife Refuge and Ducks Unlimited worked together to remove the Brown Farm Dike and restore 308 ha of the Refuge. Construction began in 2009, but monitoring efforts have continued through 2015.

Along with 57 ha wetlands restored by the Nisqually Indian Tribe, the Nisqually Delta represents the largest tidal marsh restoration project in the Pacific Northwest to assist in recovery of Puget Sound salmon and wildlife populations. Over the past decade, the Refuge and close partners, including the Tribe and Ducks Unlimited, have restored more than 35 km of the historic tidal slough systems and re-connected historic floodplains to Puget Sound, increasing potential salt marsh habitat in the southern reach of Puget Sound by 50%. Estuarine restoration of this magnitude and the potential contribution to restoration science is unprecedented in Puget Sound. Because the mosaic of estuarine habitats, this large-scale restoration is expected to result in a considerable increase in regional ecological functions and services, representing one of the most significant advances to date towards the recovery of Puget Sound. The US Geological Survey is the lead science agency providing science support to document habitat development and ecosystem function with large-scale restoration.

This website highlights the results of the science produced 5-years after construction took place. The hope is to inform other land managers of expectations following major restoration projects, as well as to satisfy the interest of curious citizens.