Mitigation
BSAP works with IDOT to develop and implement mitigation strategies that reduce or offset the environmental impacts of transportation projects across Illinois.
As state and federal permit holders for listed species work, BSAP biologists design and implement mitigation projects that ensure regulatory compliance, reduce environmental impacts, and improve ecological outcomes.
Our mitigation work includes listed species research, species relocations, seed collection and dispersal, long-term monitoring and evaluation of mitigation banks and restoration sites, and the development of Avoidance, Minimization, and Mitigation (AMM) Guidelines and other species-specific conservation documents.
Listed Species Research
BSAP biologists conduct research that improves understanding of how listed species respond to habitat changes and management actions.
Project Highlight
To support conservation of the Mudpuppy (Necturus maculosus), surveys were conducted to update existing Element Occurrence Records (EORs) and determine the extent of their ranges in the upstream reaches of rivers. This work provided critical data for conservation planning and habitat protection under IDOT’s Incidental Take Authorization.
Sensitive Species Relocations
BSAP biologists conduct relocation projects to protect state- and federally listed aquatic species during construction. Mussels and other sensitive organisms are carefully removed from work areas prior to in-stream activity to prevent impacts from silt plumes and disturbance.
Project Highlight
Before construction began, BSAP conducted surveys to identify mussel beds within the project right-of-way. Mussels were collected from the work area and a surrounding buffer zone, then safely relocated upstream to suitable habitat. This proactive approach minimized sediment exposure, ensured compliance, and protected aquatic resources.
Seed Collection and Dispersal
BSAP collects and disperses native plant seed to conserve rare species and enhance habitat restoration at IDOT project sites. Seed work is timed to coincide with natural flowering and fruiting cycles to maximize viability and maintain genetic diversity. Our team has conducted seed collection at multiple sites and has the facilities to clean, prepare, and store seed under controlled conditions until it is ready for use in restoration.
Project Highlight
To conserve the Decurrent False Aster, seed was collected for two consecutive years prior to construction to ensure an adequate supply. Flowering heads from multiple individuals across different microhabitats were harvested, dried under controlled conditions, and stored at low temperatures until construction was complete. When site restoration begins, seed will be broadcast across the area to support the reestablishment of the population and maintain genetic diversity.
Long-Term Monitoring and Evaluation
BSAP conducts long-term monitoring to evaluate the performance and ecological trends of IDOT mitigation banks and restoration sites. Monitoring helps assess whether vegetation, hydrology, and wildlife communities are developing as intended and meeting success criteria.
Project Highlight
A multi-year monitoring project at a wetland mitigation bank included four-season avian surveys and vegetation assessments over two decades. These data documented habitat development, species use, and ecological change through time, providing a foundation for adaptive management and improved restoration outcomes.
Avoidance, Minimization, and Mitigation Guidelines
BSAP develops species-specific Avoidance, Minimization, and Mitigation (AMM) Guidelines and conservation measures to help IDOT reduce project impacts on threatened and endangered species. These research-informed documents outline best management practices (BMPs), habitat protection approaches, and management strategies for a wide range of aquatic and terrestrial species.
To support IDOT’s commitment to responsible environmental stewardship, BSAP biologists have authored Species Action Plans, AMMs, or BMP guidance for over 40 sensitive species, including fishes, mussels, turtles, bats, pollinators, reptiles, and plants.
Project Highlight
One example outlines conservation measures for the Bluebreast Darter (Etheostoma camurum), a threatened fish found in the Wabash River drainage. The guidance provides step-by-step recommendations for site and risk assessments, seasonal work restrictions, sediment and erosion control, and habitat restoration, helping transportation projects minimize impacts to aquatic habitats while maintaining efficiency and regulatory compliance.
These and other AMM documents covering species such as the Rusty Patched Bumble Bee, Hines Emerald Dragonfly, Blanding’s Turtle, Eastern Massasauga, Indiana Bat, and Eastern Prairie Fringed Orchid support IDOT’s proactive conservation planning across Illinois.
