In 2016, EQR was contracted by the Department of Energy and Environment to restore 1,500 linear feet of stream channel within Alger Park, a seven acre park in the Anacostia watershed in Southeast Washington, D.C., where an estimated 41% of the watershed is impervious. Over time, the amount of stormwater runoff entering this stream channel caused it to become a heavily eroded gully (a water-worn ravine) with no storm water treatment or management. EQR’s goal was to restore the habitat, water quality and stability to one of the most highly eroded streams in Washington, D.C.
Restoring the Stream
To restore this stream, the project designer, Biohabitats Inc developed a stormwater step pool conveyance system for this site with a series of wetland grade controls at the bottom of the park where the water will connect to a floodplain before exiting the park through a trash rack. The construction of this design involved the import of over 4,000 cubic yards of fill dirt and 4,800 tons of a sand/woodchip mix that was used to fill the massive eroded cavities. After the channel was filled, multiple crews started the installation of approximately 1,300 tons of imbricated size boulders for the various stream structures, such as riffles, boulder grade controls, cascades and headwalls.
Another part of the construction process was to rehabilitate six stormwater outfalls that were crumbling into the stream channel because the flows had undercut the manhole structure. EQR rehabilitated each one by reinforcing the bank and installing boulder outfall protections such as headwalls or cobble swales where beehive grates were installed to slow the water exiting the pipes. We also had to import 1,600 tons of cobble as well as other aggregates to bolster the channel for the high flow events that eroded the soil in
the past.
EQR also partnered with Timmons Group, General Services, L.A Howard, Resource Industries and Empire Landscape for survey stakeout and as-builts, tree clearing and E&S control installation, cast in place concrete headwall, aggregate supply, and plant installation respectively.
Lastly, EQR was able to re-purpose most of the wood material that was generated from the clearing operations on site as either log sill structures, wetland grade controls, woody debris check dams, woody toe slope protection, in-stream woody debris, or chipped it and used as wood chips for the sand mixture.
UPDATE:
On October 9th, 2017, we celebrated the ribbon cutting of Alger Park!
Contact EQR
As environmental construction experts for over 26 years, Environmental Quality Resources is proud of our mission of working outdoors to preserve and protect our watershed in a positive way. Visit us online or give us a call at (410) -923-8680 to get more information and see if we are what you’re looking for. Looking to see what we are currently working on and more about our company? Follow us on Facebook, Instagram, LinkedIn, Twitter, and YouTube!
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