Dry Run Creek Restoration Project
The Dry Run Creek Watershed is located northeast of the confluence of Kickapoo Creek with the Illinois River and includes portions of Peoria, Peoria Heights, and West Peoria. The watershed is 1,690 acres (2.64 square miles) in size lying west of the Illinois River. There are no point source facilities or combined sewer outfalls in this watershed. The entire watershed lies within regulated MS4 areas of Peoria and Peoria Heights, with sanitary sewer service provided by the Greater Peoria Sanitary District (GPSD).
Developed areas comprise 94 percent of the watershed including Peoria Heights High School, significant roadways, and several smaller commercial areas. Much of the watershed contains single-family residential homes and is served by traditional curb and gutter and storm sewer.
Restoration Background and Future Need
Dry Run Creek Channel was “restored” circa 1994/1995 using gabion baskets to armor the channel embankments and some of the stream channel. Additionally, a sanitary sewer crosses the channel in two locations, that was protected, as well. Within the channel downstream of the eastern sanitary sewer crossing a low-flow dam was constructed, using gabion baskets with a concrete cap, to prevent channel downcutting and to retain sediment/cover over the sanitary sewer.
In summer/fall of 2019, historic catastrophic rainfall fell on Peoria County devastating the area and devastating the project site. More than half of the low-flow dam disintegrated and washed away. Once the dam washed away, all sediment over the sanitary sewer and for several hundred feet upstream, washed away.
The channel bottom dropped nearly 3 feet, exposing the sanitary sewer. Dropping the creek bed allowed for the embankment gabions to be undermined which caused sections of gabions to collapse. Because the gabions are wired together, as the baskets keeled over, they pulled the adjoining baskets down as well, setting up a “domino effect” failure. The remaining portion of the low-flow dam is still located along the north bank. The dam now redirects flow at the south bank, causing a portion of the south bank to be undermined and fail. As undermining continues today, the failure is moving both up and downstream.
Where the embankment consisted of unprotected earth, large sections of the toe failed causing significant slumps, cleaves, and mass wasting to radiate upslope imperiling the infrastructure at the top of the slope. The wasted slope materials likewise have washed downstream, and each new storm event has caused continued slumping and cleaving of the embankments, which is subsequently washed away.
In November 2019, Christopher B. Burke Engineering, Ltd. prepared a memorandum that described in detail the condition of the channel condition. Since the November visit each new heavy rainfall event has exacerbated and continues to cause bank and structural gabion, failure due to the nature of the sandy streambed and fill material (low cohesion) embankments. The site is experiencing a “domino effect” of failures.
A holistic restoration project is necessary to restore both north and south stream bank channels, as well as return the channel bottom to its original elevation to protect the underlying sanitary sewer.
The catastrophic failure of the channel is significant and the cost to restore the channel is cost prohibitive to the two adjacent landowners and the Greater Peoria Sanitary District. These failures risk the adjoining park lots, two sanitary sewer crossings, a waste transportation facility and its infrastructure, Swords Road bridge abutments and piers, and a potable water pump station located adjacent to the channel within the project area. The waste company’s infrastructure is critical to Peoria and Peoria County, since this facility is responsible for waste collection of the entire community.
The Dry Run Tributary watershed drains to Kickapoo Creek, which has pollutant load reduction goals set in the Illinois River (Peoria Area) TMDL and LRS Development - Watershed Characterization and Source Assessment Report from August 2010. Within the Dry Run Tributary watershed, urban stormwater runoff is the most prominent source of pollutants. In addition, the watershed is also tributary to the Illinois River which requires reductions in bacteria, total suspended solids, and nutrients to meet water quality goals.
Dry Run Creek is representative of many urbanized disturbed stream corridors, its impairments are representative of past poor treatment of our waterways. The stream corridor was and still is channelized, and portions are concrete and gabion lined. The channel is in sandy soils and at times is devoid of surface flow due to infiltration of surface flow. However, due to the sizeable urban watershed during periods of heavy rain fall the channel is quickly overwhelmed by flashy flood flows within the constrained channel.
Proposed Best Management Practices
The proposed project consists of restoring the north and south banks of the channel and the channel bed. The project starts with stabilizing the stream bed and protecting the two sanitary sewer line crossings. Robust armor caps will be constructed over and around the two sections of the sanitary sewer to prevent the line from failing and releasing untreated raw sewage. Once the sanitary sewer work is nearing completion, the streambank construction will commence tying in the sanitary sewer improvements into the stream embankment improvements to ensure a seamless transition from the stream bed to the slopes.
Slope restoration will consist of:
- Removal of down trees and debris, regrading of side slopes, grubbing of stumps, and revegetation of the area
- Removal of existing failed gabions and other debris from the failed areas
- Regrading/Restoration of the embankments
- Installation of new gabion baskets and riprap toe protection where needed
- The portions of the embankments that are not armored will receive soil wraps and slope re-grading and will be reseeded/planted with native vegetation.
Following construction, the contractor will be held to a 2-year maintenance and monitoring program to ensure that the improvements were successfully constructed, stabilized and revegetated.
The proposed project will result in the following benefits.
- The project will restore a severely eroding section of the stream channel and significantly reduce the excessive quantity of eroded material entering the creek and depositing further downstream.
- Prevent additional bank failure
- Protect critical infrastructure:
- Sanitary Sewer
- Potable Water Pump House
- Private Property
- Electric Utility Lines
- Solid waste management hauling facility
- Trucking company
- Bridge and roadway abutments and piers
Peoria County - Bridge Owner | City of West Peoria - Local Municipality
GFL - Landowner | Greater Peoria Sanitary District - Sanitary Sewer located within Dry Run Creek
Illinois Environmental Protection Agency - Grant Funding Source