Location: Between Irving Street and South Spring Street
Estimated Cost: $396,000
Estimated Construction Timeline: Mid April 2015
Funding Source: Federal, State, and Tribal Assistance Grants and Stormwater Utility Fund
The stream known as Pearson Branch flows out from pipes under Irving Street and back into the ground at Spring Street. A small portion of this open stream is located in Berman Park.
The upper section of the stream is a
hardened channel made of old sections of broken sidewalk, concrete
curbing, and gutters.
The area is stable in terms of erosion but does not provide a natural habitat typically found in stream corridors. The lower portion of Pearson Branch has severe stream bank erosion due to high flows.
Over time, the stream channel has widened and undercut the existing retaining wall. This has led to a collapse in many portions and the closing of a section of the footpath in Berman Park. The increased stress on the stream banks has produced steep slopes along the stream corridor making it unsafe for pedestrians to walk along its edge.
The erosion of the stream and subsequent sediment transport and road grit accumulation has also destroyed the habitat necessary for diverse aquatic life.
Natural stream channel restoration techniques will be used to remove the existing hardened channel and to stabilize 360 feet of stream channel, banks, and bed. The stream will be widened to approximately 30 feet and shifted toward the park and away from residences.
The new alignment and subsequent construction of the project requires the removal of nearly 50 trees of varying sizes. An effort will also be made to remove invasive plant species within the project limits. Approximately 390 native canopy and understory trees and shrubs will be planted along the banks in order to restore and stabilize the riparian habitats.
The stream bed will be graded and shaped to improve water flow and increase pool habitat. Techniques such as cross vanes, rock toe protection, constructed riffles, and step pools will be used to prevent future erosion, control the direction of the flow, and prevent scour of the stream bed while providing habitat for wildlife.
The walking path will be relocated to allow for pedestrians to enjoy the enhanced aesthetic value of Pearson Branch and Berman Park.