Low Impact Development (LID) is a site design strategy that maintains or replicates predevelopment hydrology through runoff source control by reducing and disconnecting impervious areas, lengthening flow path and runoff time, and protecting sensitive features including: riparian buffers, wetlands, steep slopes and flood plains.

Examples of these structures include permeable pavement surfaces, grass buffers, porous landscape detention and green roofs. Urban Drainage and Flood Control District provides details on many LID structures in Volume 3 of the Drainage Criteria Manual under the 4-Step Process. http://www.udfcd.org/downloads/down_critmanual.htm

This photo essay has been compiled to show examples of LID structures in Colorado. 

Use the back and next links at the top and bottom of each page to navigate through database, visit the summary table to find a particular slide, or click on one of the following links to jump directly to a section of interest:

• Vegetative Filters: water quality benefits through straining and some runoff reduction benefits depending on the absorption and infiltration capacity of the soils underneath the vegetation.

• Grass Buffer

• Grass Swale

• Vegetative Infiltration: water quality benefits and increased runoff protection potential such as the water quality capture volume, according to structure design and capabilities of soil/engineered media under vegetation.

• Porous Landscape Detention

• Bio Swale

• Green Roof

• Structural Infiltration: Greatest water quality and runoff reduction potential. Possible to infiltrate WQCV (0.5") and EURV (1.1") according to design and subgrade soils. May also provide detention capacity for major event.

• Permeable Interlocking Concrete Pavement (PICP)

• Porous Asphalt (PAP)

• Pervious Concrete (PCP) - Updated Moratorium Recommendation

• Pervious Concrete tips by Indiana Ready Mixed Concrete Association
  This document is provided for information and discussion purposes as stormwater stakeholders continue to look for a solution to Urban Drainage and Flood Control District's requested moratorium on pervious concrete installations.

• Extra runoff reduction and LID examples

• "Green" Parking Lot

• Mountain Stormwater

• Level Spreader

Major Storm Detention Structures

Although not runoff reduction or LID, detention BMPs displaying habitat and additional water quality benefits may be featured here.

• Grant Ranch EDB and Micropool

• Extended Detention Basin - Note: an EDB is not a volume-reducing or LID technique

• High Point Cascading Integrated Water Quality Pond

• 71st and Argonne Street, Denver, CO

• Sand Filter

This database is compiled and maintained by the CASFM Stormwater Quality Committee.  Please submit photos and summaries for other structures that may be added to this list. Also send additional information about existing structures in this database to Herman Feissner at hfeissner@feissnerconsulting.com or Holly Piza at hpiza@udfcd.org.