BMPs

Much of the cause of our polluted waters comes from stormwater runoff which enters our streams and rivers without treatment.

Stormwater becomes polluted by:

oil and grease from roadsides

pesticides from lawns and agriculture

sediment from construction sites

carelessly discarded trash

What is a BMP?

A BMP, or Best Management Practice, is a stormwater management and/or conservation practice that effectively controls movement of pollutants, prevents degradation of soil and water resources, and is compatible with the land use. BMPs can be divided into two categories: structural and non-structural.

Examples of BMPs:

BMP Name	Primary Function	Description
Alternative Pavers	Infiltration	Permeable or semi-permeable surfaces that can replace asphalt and concrete and can be used for driveways, parking lots, and walkways. The two broad categories are paving blocks and other surfaces including gravel, cobbles, wood, mulch, brick, and natural stones.
Alternative Turnaround	Capture, Infiltration	Designs for end-of-street vehicle turnaround that replace cul-de-sacs and reduce the amount of impervious cover created in residential neighborhoods.
Bioretention	Capture, Filtration, Infiltration, Storage	Soil and plant-based stormwater management practices designed to filter runoff from developed communities by mimicking vegetated systems that naturally control hydrology through detention, filtration, infiltration, and evapotranspiration.
Constructed Wetlands	Capture, Filtration, Storage	Created wetlands systems that perform a series of pollutant removal mechanisms including sedimentation, filtration, absorption, microbial decomposition and vegetative uptake.
Disconnected Non-Rooftop Areas	Infiltration	Directing sheet flow runoff from impervious surfaces (driveways, streets, sidewalks) to pervious surfaces instead of storm drains.
Disconnected Rooftop Runoff	Infiltration	Disconnecting the rooftop drainage pipe and allowing it to infiltrate into the pervious surface, thereby reducing the impervious surface area.
Dry Extended Detention	Capture, Infiltration, Storage	A basin with an outlet designed to detain the runoff from a water quality storm for some minimum duration (ex. 24 hours) which allows sediment particles and associated pollutants to settle out.
Dry Swale	Capture, Infiltration	A type of grassed swale, a dry swale is an open drainage channel explicitly designed to detain and promote the filtration of runoff through an underlying fabricated soil media.
Dry Well	Capture, Infiltration	A type of on-lot treatment practice used to infiltrate rooftop runoff, where the storm drain is directed to an underground rock-filled trench that is similar in design to an infiltration trench.
Filter Strips (grassed)	Filtration	Also known as vegetative buffer strips, these are vegetated sections of land similar to grassed swales except they are essentially flat with low slopes and are designed to promote sheet flow of stormwater runoff. Filter strips are often used as pretreatment for downstream BMPs.
Grassy Swale	Capture, Infiltration	A swale refers to a series of vegetated open channel management practices designed specifically to treat and attenuate runoff for a specific water volume.
Green Parking	Capture, Infiltration	Green parking lot techniques include setting maximums for the number of parking lots created, minimizing the dimensions of parking lot spaces, utilizing alternative pavers in overflow parking areas, using bioretention areas to treat stormwater, and encouraging shared parking.
Green Roof	Capture, Storage	A multi-layer constructed material consisting of a vegetative layer that effectively reduces urban runoff by reducing the amount of impervious cover.
Infiltration Basins	Capture, Filtration, Infiltration	Relatively large, open depressions that allow runoff to be percolated through the bottom or sides and the sediment to be trapped in the basin.
Infiltration Trenches	Capture, Filtration, Infiltration	An excavated trench that has been back filled with stone to form a subsurface basin. Storm water runoff is diverted into a trench and stored until it can be infiltrated into the soil.
Minimize Clearing	Capture, Infiltration	A practice where land cleared for construction is kept to a minimum. The limits of disturbance are clearly identified, and clearing is restricted only to the areas where clearing is absoluetely necessary for construction access, buildings, roads, and utilities.
Narrow Streets	Infiltration	The use of narrower streets to reduce the amount of impervious cover created by new residential development, and in turn, reduce the runoff and associated pollutant loads.
Native Vegetation Preservation	Capture, Filtration	Preserving vegetation on construction sites is a cost-effective alternative to wholesale clearing and subsequent need for mitigation and engineered hydrologic control measurers.
Open Space Design	Infiltration	Also known as conservation development or cluster development, open space design concentrates dwelling units in a compact area in one portion of the site in exchange for providing open space and natural areas elsewhere on the site.
Pervious Pavement Systems	Capture, Filtration, Storage	Pavement that allows storm water to infiltrate into underlying soils promoting pollutant treatment and recharge.
Phased Construction	Capture	In phased construction, soil is disturbed as little as possible during all construction phases to minimize erosion and prevent sediment from migrating off site. It is also imperative to limit the time of subsurfacesoil exposure.
Rain Barrels	Capture, Storage	Rain barrels retain a predetermined volume of rooftop runoff that can be used during drier times.
Rain Garden (aka Bioretention)	Capture, Filtration, Infiltration, Storage	A small residential depression planted with native wetland and prairie vegetation, rather than a turfgrass lawn, where runoff collects and infiltrates.
Riparian Buffer	Capture, Filtration, Infiltration	Buffers are strips of herbaceous and woody vegetation along streams and open bodies of water. They help reduce the impact of runoff by trapping sediment and sediment-bound pollutants; encouraging infiltration; and slowing and dispersing stormwater flows over a wide area. They also help preserve streambank stability by reinforcing the soil with root systems.
Sand and Organic Filters	Infiltration	A self-contained bed of sand used to treat wastewater or diverted stormwater runoff; the water subsequently is collected in underground pipes for additional treatment or discharge.
Stormwater Planter	Capture, Infiltration, Storage	The Stormwater Planter is designed with an impervious bottom or is placed on an impervious surface. Flow control is obtained by storing the water in a reservoir above the soil. The additional benefit of pollutant reduction is achieved as the water filters through the vegetation and soil. Planters may be in-ground or above grade.
Topsoil Stockpiling	Capture	A practice of phased construction, where the topsoil is put into piles and conserved for later use on the site. This measure can preserve valuable topsoil, preventing sediment, nutrients, and organic matter from contaminating waterways.
Tree Establishment	Capture, Filtration	Establishment or re-establishment of a stand of trees on cleared land will reduce erosion and protect or enhance water quality.
Tree Preservation	Capture, Filtration	Maintenance of existing trees and shrubs.
Vegetated Channel/ Swale	Conveyance, Filtration, Infiltration, Storage	Vegetated channels are broad, shallow, natural, or constructed channels with a dense stand of vegetation covering the side slopes and channel bottom. They slowly convey stormwater runoff, and in the process promote infiltration, reduce flow velocities, and pretreat stormwater.
Wet Pond	Capture, Infiltration, Filtration, Storage	A constructed system with sufficient capacity to detain flood volumes and to store the runoff volume in a permanent pool.
Wet Swales	Capture, Infiltration	A type of grassed swale, a wet swale is an open channel or depression explicitly designed to retain water or intercept groundwater for water quality treatment.
Wetlands Preservation	Filtration, Infiltration, Storage	Wetlands provide many benefits including water quality improvement, flood protection, habitat, and erosion control. Wetlands help protect water quality by intercepting pollutants in surface water runoff before they reach surface water bodies, removing or retaining nutrients and sediment, and processing chemical and organic waste.