Illinois Rivers, Lakes, and Streams Act Glossary: Key Terms & Definitions for Developers and Consultants

Illinois Rivers, Lakes, and Streams Act Key Terms & Definitions

Ambient Water Quality Standards: Regulatory standards established by the Illinois Pollution Control Board that define the maximum permissible levels of pollutants in a water body to protect its designated uses, such as aquatic life, recreation, and public water supply. (35 Ill. Adm. Code 302)

Aquatic Life: Organisms that live in or depend on water bodies for survival, including fish, invertebrates, amphibians, and plants. The Illinois Rivers, Lakes, and Streams Act aims to protect and maintain conditions suitable for aquatic life in the state's water resources.

Best Management Practices (BMPs): Structural, non-structural, and managerial techniques used to prevent or reduce pollution from entering water bodies. BMPs are often required as part of permits issued under the Illinois Rivers, Lakes, and Streams Act.

Designated Uses: The specific uses of a water body that are protected by water quality standards, such as aquatic life, recreation, and public water supply. The Illinois Rivers, Lakes, and Streams Act requires that water quality be maintained to support the designated uses of each water body.

Dredge and Fill Activities: The removal or addition of material from or to a water body, which can impact water quality and aquatic habitats. The Illinois Rivers, Lakes, and Streams Act regulates dredge and fill activities to minimize their adverse effects on the state's water resources.

Effluent Limitations: Restrictions on the quantity, rate, and concentration of pollutants discharged into a water body from a point source. Effluent limitations are often included as conditions in permits issued under the Illinois Rivers, Lakes, and Streams Act.

Exotic Species: Non-native plant or animal species introduced into an ecosystem, which can potentially harm native species and disrupt ecological balance. The Illinois Rivers, Lakes, and Streams Act prohibits the introduction of exotic species into the state's water bodies.

Impaired Waters: Water bodies that do not meet water quality standards for their designated uses due to pollution or other factors. The Illinois Rivers, Lakes, and Streams Act requires the identification and restoration of impaired waters in the state.

Invasive Species: Non-native plant or animal species that can spread rapidly and cause harm to native species, ecosystems, and human activities. The Illinois Rivers, Lakes, and Streams Act prohibits the introduction of invasive species into the state's water bodies.

Mitigation: Actions taken to avoid, minimize, or compensate for the adverse impacts of a regulated activity on a water body. Mitigation may be required as a condition of permits issued under the Illinois Rivers, Lakes, and Streams Act.

Navigable Waters: Waters that are subject to the jurisdiction of the United States under the Clean Water Act, as determined by the U.S. Army Corps of Engineers. The Illinois Rivers, Lakes, and Streams Act applies to all navigable waters within the state.

Nonpoint Source Pollution: Pollution that originates from diffuse sources, such as runoff from agricultural lands or urban areas, rather than from a specific point source. The Illinois Rivers, Lakes, and Streams Act includes provisions to address nonpoint source pollution and its impacts on water quality.

Permit: An authorization issued by the Illinois Department of Natural Resources (IDNR) that allows a regulated activity to proceed under specified conditions. Permits are required for many activities that may impact rivers, lakes, and streams under the Illinois Rivers, Lakes, and Streams Act.

Point Source: Any discernible, confined, and discrete conveyance from which pollutants are or may be discharged, such as a pipe, ditch, or channel. Point sources are regulated under the Illinois Rivers, Lakes, and Streams Act and may require permits.

Pollutant: Any substance that can degrade water quality or harm aquatic life, including chemicals, waste materials, and heat. The Illinois Rivers, Lakes, and Streams Act prohibits the discharge of pollutants into water bodies without a permit.

Public Waters: All waters within the state of Illinois that are subject to the jurisdiction of the IDNR under the Illinois Rivers, Lakes, and Streams Act, including navigable and non-navigable waters.

Riparian Zone: The area of land adjacent to a water body that directly influences and is influenced by the water body. The Illinois Rivers, Lakes, and Streams Act includes provisions to protect and restore riparian zones as part of its overall goal of maintaining water quality and aquatic habitats.

Section 401 Water Quality Certification: A certification issued by the Illinois Environmental Protection Agency (IEPA) that a proposed activity will not violate water quality standards. Section 401 certification is required for many activities regulated under the Illinois Rivers, Lakes, and Streams Act that also require a federal permit.

Stormwater: Water that originates from precipitation events and flows over land or impervious surfaces, potentially carrying pollutants into water bodies. The Illinois Rivers, Lakes, and Streams Act includes provisions to manage stormwater and its impacts on water quality.

Total Maximum Daily Load (TMDL): The maximum amount of a pollutant that a water body can receive and still meet water quality standards. TMDLs are developed for impaired waters and may be used to guide permit conditions and other actions under the Illinois Rivers, Lakes, and Streams Act.

Water Pollution: The alteration of the physical, chemical, or biological properties of a water body in a way that harms its designated uses or aquatic life. The Illinois Rivers, Lakes, and Streams Act aims to prevent and reduce water pollution in the state's rivers, lakes, and streams.

Water Quality Standards: Regulatory standards that define the water quality goals for a water body and the criteria necessary to protect its designated uses. Water quality standards are established by the Illinois Pollution Control Board and enforced through the Illinois Rivers, Lakes, and Streams Act.

Watershed: The land area that drains into a particular water body or system of water bodies. The Illinois Rivers, Lakes, and Streams Act emphasizes a watershed-based approach to water resource management and protection.

Wetlands: Areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support vegetation adapted for life in saturated soil conditions. Wetlands are protected under the Illinois Rivers, Lakes, and Streams Act due to their important ecological functions and values.