2016 (Google Earth), 2017 (Josh Duplechian), 2020 (Jason Schilling)
OHA works with our team of partners both in and near the stream to restore the Triple Creek wetland. We mimic the work of beavers in the stream and establish native plants near the stream, to help the site become a thriving wetland again.
Below is a general video about our work in the stream. To the right is a series of videos designed for restoration practitioners and people who want to understand this restoration tool, to share about this project and what we have learned so far.
Beaver dam analogs, or BDAs, are designed to do different kinds of work in the stream. Some slow the water down and back it up, while others push the stream into the bank, which pulls sediment out, to be used in building the stream bottom higher.
Photo: BDA 30, the upstream-most beaver dam analog.
This is the end result we are aiming for: the BDA slows the water down, backs it up, and causes sediment to build up on the streambed. As a result, high flows connect with the floodplain, making the wetland wet again!
Virtual Field Guide to Beaver Dam Analogs
Question 1: What happened to this wetland?
Question 2: What do you aim to do?
Question 3: How are these BDAs designed?
Question 4: How are you installing the posts?
Question 5: Which kind of post driver should we use?
Question 6: How do you choose post length?
Question 7: How easily do the posts go in?
Question 8: Where should we site BDAs?
Question 9: What weave materials do you use?
Question 10: How do you use conifer boughs?
Question 11: Show us how you weave the BDAs!
Question 12: What changes have you seen?
How do we mimic beavers? The restoration team is focused on reducing the severe stream channel downcutting that disconnected Myers Creek from the floodplain. The project design mimics the work of beavers by using lines of wooden posts that are woven with branches to slow and redirect stream flows as needed. These structures, known as beaver dam analogues or BDAs, help capture sediment to build the streambed back up and raise the water table. They also help make the channel longer while reducing its slope, making the system more stable.
Check these structures out and how the stream interacts with them to create positive change:
Practitioners: Read our 2018 draft case study — and please check back later as a new version is in the works!
A diverse and robust buffer zone will not only improve native vegetation but will encourage beavers to recolonize the area, and modify and maintain the site into the future.
Volunteers of all ages have helped plant several willow species, dogwood, cottonwood, chokecherry, elderberry, Douglas-fir, spruce, snowberry, spirea, and other species of trees and shrubs. As these plants grow, they will provide shade, healthy wetland function, habitat for wildlife
Beavers have already shown increased interest in the project site, starting just a few days after construction began in 2016. Beavers even wove a post line themselves in 2017, before the project team could get to it!