Upper Little Patuxent Design and Build Stream Restoration
This project was awarded the Maryland Department of Transportaion Environmental Award. The Environmental Excellence award recognizes this project as an excellent example of using the SHA partnering procedures during the design-build process to increase environmental benefits, reduce costs, and accelerate completion.
The Ecotone (Prime) and JMT team provided design, permitting and construction for Marylands first design-build stream restoration project. The restoration of the Upper Little Patuxent River emphasized water quality improvements, increased flood attenuation, and significant reductions of sediment and nutrients to downstream receiving waters. To accomplish these objectives, Ecotone/JMT implemented a highly connected stream and lower floodplain wetland system that directly removed the highly-erodible and nutrient-rich sediments, which have impaired the valley bottom and created a highly incised stream channel. This geomorphically-stable solution resulted from a more frequent hydraulic connection to bankfull and higher flows, increased flood flow attenuation, reduced shear stresses, increased vegetative stability, and improved water quality.
A large component of the stream and floodplain restoration design is increased chemical and biological functions. The lower floodplain allows for the creation of a dense, native wetland plant community increasing nutrient processing and microbial processes essential to the denitrification process. The high connectivity of plants to ground and surface waters provides aquatic food sources and habitat and promotes native plant biodiversity and long-term vegetative stabilization.
In total, more than 3.5 additional acres of wetlands were created at a lower elevation and connected to the base flow of the channel.
Eroded Stream Banks.
View of toewood with coir matting.
View of completed stream with vegetated banks.