Floodplains

Floodplains are the areas of low-lying ground adjacent to rivers, formed mainly of nutrient-rich river sediments and subject to flooding after storms and heavy snowmelt.

Source: Floodplains by Design

Aerial photo of Hansen Creek restoration site in Skagit County, WA. October 15, 2010. Photo: Kari Neumeyer/NWIFC

OVERVIEW

Nature inspires new approach to flood control

Scientists are rethinking floodplain management in Puget Sound. Can we have our farms and salmon too?

RELATED ARTICLES

5/11/2021

Floodplains and Estuaries Implementation Strategy

This article provides an overview and a link to further information about the Floodplains and Estuaries Implementation Strategy. Implementation Strategies (Strategies) are plans for accelerating progress toward the 2020 ecosystem recovery targets for the Puget Sound Vital Signs. The Strategies are developed collaboratively with technical, professional, and policy experts and with local and regional input. They are funded by the Environmental Protection Agency.

2016 aerial view of completed Calistoga Reach levee project in Orting, WA. Image courtesy: CSI Drone Solutions and Washington Rock Quarries, Inc. Video: https://www.youtube.com/watch?v=2H_NK6U2_zw
4/11/2017

Floodplain projects open doors to fewer floods and more salmon

A new approach to flood control is taking hold across Puget Sound. Rivers, scientists say, can be contained by setting them free. Conservationists hope this is good news for salmon recovery.

Submerged marsh in Fisher Slough. Image courtesy of NOAA.
2/5/2014

Floodplains by Design

Floodplains by Design identifies floodplains in Puget Sound with multiple benefit potential and use information on flood risk to inform ecosystem restoration. 

Report cover
3/25/2024

Habitat protection and restoration in Puget Sound: An overview of Strategic Initiative Lead investments 2016-2023

Between 2016 and 2021, $21 million provided by the Environmental Protection Agency (EPA) funded 100 different projects to protect, restore, and study critical habitats in Puget Sound. This publication presents an overview of many of the key accomplishments and lessons learned from these efforts. It is a catalog of some of the ‘big ideas’ presented by the scientists and conservationists involved, and it is meant to inform and guide future Puget Sound recovery efforts. This overview is based on the full synthesis report, “Synthesis of Habitat Strategic Initiative Lead 1.0 2016-2023 Investments for Puget Sound Recovery," published by the Puget Sound Institute.

Aerial view of Interstate 5 stretching across a large area of land covered by brown flood waters from the Nooksack River in the foreground with mountains and Puget Sound in the distance and grey skies above.
10/30/2023

Studies target increasing flood risks

All across the region, communities are finding that rising seas and rising rivers are two sides of the same coin. New research funded by the Environmental Protection Agency may help managers target their responses to climate-fueled flood risks in Puget Sound. The following article was commissioned by the Habitat Strategic Initiative Lead (HSIL), a cross-agency team co-led by the Washington Departments of Fish and Wildlife and Natural Resources.

10/30/2023

多項研究以日趨升高的洪水風險為目標

本區域各地的社區發現,海平面上升和河水上漲是一體兩面的問題。氣候變遷使得Puget 海灣面臨愈來愈高的洪水風險,環境保護局贊助的新研究可能有助於主管機關找出因應之道。

10/30/2023

Những nghiên cứu nhắm đến các rủi ro ngày một nhiều về lũ lụt

Trên toàn khu vực, các cộng đồng đang nhận thấy rằng tình trạng mực nước biển và mực nước sông dâng lên có mối liên hệ chặt chẽ. Nghiên cứu mới do Environmental Protection Agency (Cơ Quan Bảo Vệ Môi Sinh) tài trợ có thể giúp các nhà quản lý hướng các biện pháp ứng phó của họ vào các rủi ro lũ lụt do khí hậu tại Puget Sound.

10/30/2023

Los estudios señalan el aumento del riesgo de inundaciones

En toda la región, las comunidades están descubriendo que el aumento del nivel del mar y los ríos son dos caras de la misma moneda. Una nueva investigación financiada por la Agencia de Protección Ambiental puede ayudar a los administradores a enfocar sus respuestas a los riesgos de inundaciones provocadas por el clima en el estrecho de Puget.

A beaver swimming in a pond with vegetation in the background.
9/26/2023

Can the age-old affinity between beavers and salmon be restored?

Salmon restoration groups are learning how to work with beavers to create better salmon habitat. The process hinges on reducing human-beaver conflicts while taking a natural approach to ecosystem recovery. The beavers are happy to help. 

Report cover
7/14/2023

Synthesis of selected NEP Watershed Lead Organization grants administered by the Department of Ecology part 2

A 2023 report from the University of Washington Puget Sound Institute synthesizes past Watershed Lead Organization Program grants to support the EPA-funded Land Development and Cover and Floodplains and Estuaries Implementation Strategies. The report offers lessons learned from the habitat restoration and land acquisition-focused grants.

Mudflats at low tide with numerous small mounds of sediment
5/15/2022

'Invertebrate engineers' combat sea level rise

A pilot project to create a 'living dike' in Canada's Boundary Bay is designed to help a saltwater marsh survive rising waters due to climate change.

Two people operating a bulldozer at the intersection of two flooded streets in Sumas, Washington. In the background, partially submerged cars are parked in front of the library.
3/22/2022

Rethinking flood control for the Nooksack River

Can restoring the natural balance of the Nooksack River also reduce flood risks? Officials on both sides of the U.S.-Canada border are taking note as climate change raises the stakes. 

Graphic image of tidal channels
2/25/2022

How do you build an estuary? The answer lies in Puget Sound’s geologic history

Puget Sound is often referred to as the second largest estuary in the contiguous United States behind only Chesapeake Bay, but its overall size may be less important than its complexity. The place is defined by the mixing of saltwater from the ocean and freshwater from creeks and rivers that create an almost alchemical transformation of habitat. In this article, we look at the geologic forces that formed Puget Sound and made it the dynamic system that we understand today.   

Winter scene of marsh at high tide two conifer trees reflected on water in the foreground; snow covered mountain in the background.
11/15/2021

Making room for salmon

How can Puget Sound generate more salmon? That question has been at the center of ecosystem recovery efforts for decades. But even as scientists and conservationists make progress on many fronts — from breaching dams to cleaning up the water — they have faced one especially complicated and frustrating limitation: Salmon need more estuaries. We look at how local tribes are working to restore this critical habitat.

View of river with reflection of clouds and vegetation
10/28/2021

Puget Sound National Estuary Program Synthesis of Integrated Floodplain Management in Selected Puget Sound River Deltas

A 2021 synthesis report from the University of Washington Puget Sound Institute synthesizes leading integrated floodplain management approaches to support the EPA-funded Floodplains and Estuaries Implementation Strategy.

Tidal forest as viewed from an inner waterway of Otter Island in the Snohomish River estuary. Photo: Jeff Rice/PSI
1/21/2019

Tidal forests offer hope for salmon

Can scientists bring back the lost tidal forests of Puget Sound? It could take generations, but restoring this rare habitat will pay big dividends for Puget Sound’s salmon.   

Cassells Point, Duwamish River, WA, ca. 1891. View is to the east, with streetcar bridge crossing the Duwamish River near South Park in the background. Photo credit: University of Washington Special Collections, Frank Laroche Photograph Collection.
11/8/2018

Puget Sound River History Project

The Puget Sound River History Project at the University of Washington features historical topographic data for Puget Sound's river systems.  

Dean Toba, a scientific technician with the Washington Department of Fish and Wildlife, operates the agency’s screw trap on the Skagit River. The trap helps biologists estimate the number of juvenile salmon leaving the river each year. Photo: Christopher Dunagan, PSI
8/4/2017

Are we making progress on salmon recovery?

In recent decades, hundreds of millions of dollars have been spent to restore habitat for Puget Sound salmon. In this article, we look at how scientists are gauging their progress. Are environmental conditions improving or getting worse? The answer may depend on where you look and who you ask.

Fir Island Farms habitat restoration monitoring in Skagit County. Project provides rearing habitat for young threatened Chinook salmon along with other wildlife. Copyright: Bob Friel
3/30/2017

Finding a strategy to accelerate Chinook recovery

As threatened Chinook populations in Puget Sound continue to lose ground, the state is looking to new strategies to reverse the trend. In the Skagit watershed, the scientists — and the fish — are among those leading the way. 

Birch Bay. Photo by Jeff Rice
12/21/2015

Birch Bay characterization and watershed planning pilot – taking action

A 2015 report from the Whatcom Conservation District and Whatcom County describes a pilot watershed characterization study focusing on the Terrell Creek and Birch Bay areas. The report and related appendices are available for download. 

Report cover for State of Knowledge: Climate Change in Puget Sound
11/16/2015

State of Knowledge: Climate Change in Puget Sound

A 2015 report from the University of Washington provides the most comprehensive assessment to date of the expected impacts of climate change on the Puget Sound region.

Woodard Creek Basin water resource protection study report cover
11/9/2015

Guiding growth-healthy watersheds: Woodard Creek Basin water resource protection study

An EPA-funded study by the Thurston Regional Planning Council identified recommended strategies and actions to protect and improve water quality and aquatic resources in the Woodard Creek  Basin. 

McLane Creek Basin water resource protection study report cover
11/9/2015

Guiding growth-healthy watersheds: McLane Creek Basin water resource protection study

An EPA-funded study by the Thurston Regional Planning Council identified recommended strategies and actions to protect and improve water quality and aquatic resources in the McLane Creek  Basin. 

Black Lake Basin water resource protection study report cover
11/5/2015

Guiding growth-healthy watersheds: Black Lake Basin water resource protection study

An EPA-funded study by the Thurston Regional Planning Council identified recommended strategies and actions to protect and improve water quality and aquatic resources in the Black Lake Basin. 

Puget Sound portion of a 1798 chart showing "part of the coast of N.W. America : with the tracks of His Majesty's sloop Discovery and armed tender Chatham / commanded by George Vancouver, Esqr. and prepared under his immediate inspection by Lieut. Joseph Baker." Credit: Library of Congress, Geography and Map Division.
9/18/2015

Puget Sound: A uniquely diverse and productive estuary

Puget Sound is the second largest estuary in the contiguous United States. Today, we understand that estuaries — where freshwater and saltwater merge — are among the most productive places for life to exist.

Hansen Creek Alluvial Fan and Wetland restoration project (Poster #1)
7/28/2015

Hansen Creek alluvial fan and wetland restoration project

Habitat restoration was undertaken in 2009-2010 on lower Hansen Creek, Washington. The project converted 140 acres of isolated floodplain into 53 acres of alluvial fan and 87 acres of flow-through wetlands.