millbrook park stream

Water and Sewer

Millbrook Exchange Park Stream Restoration

We restored a stream near Perry Creek to improve its function and reduce pollution to the stream.

The project is supported through a grant from Clean Water Management Trust Fund. 

Project Details

 
Type:
Lakes, Streams, and Dams
Budget:
$300,000
Project Lead:
Stormwater Management
Contractors:
NCSU Stream Restoration Program

Contact

 

Heather Dutra
Senior Engineer
919-996-4012

Lead Department:
Engineering Services
Service Unit:
Stormwater

Planning

This phase is complete.

Phase Contacts

 

Heather Dutra
Senior Engineer
919-996-4012

Lead Department:
Engineering Services

Design

This phase is complete.

Phase Contacts

 

Heather Dutra
Senior Engineer
919-996-4012

Lead Department:
Engineering Services

Construction

This phase is complete.

Phase Contacts

 

Heather Dutra
Senior Engineer
919-996-4012

Lead Department:
Engineering Services

Complete

This project is complete. We installed 11 stone dams and a vertical control structure to prevent streambank erosion. We also planted trees and shrubs in the project area. 

North Carolina State University will continue to study the stream until 2020 to track the benefits of using this innovative stream restoration technique.

Phase Contacts

 

Heather Dutra
Senior Engineer
919-996-4012

Lead Department:
Engineering Services

History

This stream flows to Perry Creek and passes through Millbrook Exchange Park. It receives stormwater runoff from a 167-acre largely developed drainage area.  Erosion caused by stormwater runoff coming from the surrounding area caused the stream’s bed to drop several feet below its natural level. The stream was between 5-12 feet with high banks.

In this condition - The stream lacks many key functions that preserve it and protect wildlife in the area. With the design, the stream bed will go from 12 feet deep to 3 feet deep (in some places along the stream). 

This stream is also unique because it only fills up with water during rainy seasons or heavy rain storms. So, it may take several years for the streambed to be completely repaired. 

Schedule

Date Activity
Spring 2018 Project design and permitting/bid process complete
Fall 2018 Project construction begins
Spring 2019 Project construction complete (Monitoring will continue through 2020)

The Restoration

The restoration uses a low-cost and unique design that includes fitting 11 small stone dams in the stream that will fill in with sediment (i.e. silt, sand, and gravel) over time and raise the streambed. This restoration technique reduces the amount of sediment downstream, transforms the energy and flow of the stream, and prevents any further erosion to the streambank.