The City of Belvidere, Illinois engaged C.E.S., Inc. to address chronic sediment accumulation and maintenance challenges in the 6th Street Channel, a municipal stormwater conveyance that had become increasingly difficult and costly to maintain. The City’s original plan called for lining the channel with concrete, but regulatory agencies would not permit a hardened channel due to impacts on water quality and aquatic habitat. C.E.S. retained A3 Environmental Consultants (A3E), operating as Olson Ecological Solutions at the time, to reimagine the channel as a naturalized waterway that would solve the City’s maintenance problems while satisfying regulatory requirements and enhancing ecological function.
Channel Naturalization Design
A3E key staff developed a comprehensive ecological design that transformed the channel from a maintenance liability into a functional, naturalized waterway. The design incorporated a sediment basin at the upstream end to capture incoming sediment loads, with a series of rock check dams positioned throughout the channel to create concentrated maintenance areas where sediment could be efficiently removed. The channel was deepened to support a combination of permanent open water pockets and emergent vegetation, reducing the frequency and difficulty of routine maintenance while improving stormwater conveyance.
A3E designed three distinct planting zones tailored to the channel’s hydrology. Wetland sedge plugs were specified for the channel bottom and water’s edge, where species such as native rushes and sedges grow into the water to promote clean water infiltration and provide habitat for aquatic life. A transition zone of native grasses and forbs was designed for the mid-slopes to stabilize the banks and manage the interface between wet and upland conditions. At the top of the banks, A3E designed a pollinator conservation mix featuring native wildflowers including butterfly milkweed (Asclepias tuberosa), compass plant (Silphium laciniatum), coneflower (Echinacea sp.), cup plant (Silphium perfoliatum), and coreopsis (Coreopsis lanceolata)—providing critical pollinator habitat while reducing long-term mowing requirements.
Naturalization Stream Project Belvidere IL
Planting Specifications & Performance Standards
A3E authored detailed planting specifications that established measurable performance standards for each planting zone across a multi-year establishment period and established qualifications for the ecological contractor responsible for installation and stewardship.
Ecological Monitoring & Adaptive Management
Following planting in 2023 and 2024, A3E conducted a preliminary site assessment in June 2025 to evaluate performance against the established standards. The assessment found that the channel naturalization was largely performing as expected, and A3E also identified areas requiring adaptive management.
The 6th Street Channel project demonstrates A3E’s ability to deliver ecologically sound solutions to complex municipal infrastructure challenges. By converting a concrete-lined channel proposal into a naturalized waterway with native habitat, A3E helped the City of Belvidere reduce long-term maintenance costs, improve stormwater quality, and create lasting pollinator and aquatic habitat—turning a municipal maintenance problem into a community ecological asset.
