Cold Weather Climate Issues

This page contains some general issues that might be encountered in cold weather climate areas.  Some of the topics have been elaborated on in the Design This page contains some general issues that might be encountered in cold weather climate areas.  Some of the topics have been elaborated on in the Design Guide, while others have not.  This page is not meant as a comprehensive resource.  More informational descriptions and web links will be added as they become available.  If specific issues are in question please conduct further searches on the internet and/or send an email to info<at>lowimpactdevelopment.org. Thanks.

Cold Weather and LID
Robert M. Roseen
Presented at the Stormwater BMP Technology Demonstration Workshops at UNH in October/November 2004.
http://www.unh.edu/erg/cstev/Presentations/

Bioretention
Bioretention is not an appropriate BMP at locations where the water table is within 1.8 meters (6 feet) of the ground surface and where the surrounding soil stratum is unstable.  In cold climates the soil may freeze, preventing runoff from infiltrating into the planting soil. The BMP is also not recommended for areas with slopes greater than 20 percent, or where mature tree removal would be re-quired. Clogging may be a problem, particularly if the BMP receives runoff with high sediment loads.

Bioretention provides stormwater treatment that enhances the quality of down-stream water bodies. Runoff is temporarily stored in the BMP and released over a period of four days to the receiving water. The BMP is also able to provide shade and wind breaks, absorb noise, and improve an area’s landscape.

Tree and shrub species that are more tolerant to cold winds (e.g., evergreens) should be placed in windier areas of the site.

Disconnectivity
This technique involves avoidance of pipes and channels that directly convey stormwater from source to outlet by insertion of overland flow planes, small check dams, etc. These techniques can be effective at reducing energy, volume, peak, and maintaining natural flow paths. Many highway drainage systems that are already decentralized are still well connected to receiving waters. Often ditches are lined or armored with paved materials where alternative, more water quality friendly approaches may achieve the same erosion control and maintenance goals. Another advantage of disconnectivity in the highway environment is avoidance of piped drainage in cold climates. Frozen water in drainage systems creates a design and maintenance problem that can sometimes be avoided by discharge to open channels and pervious surfaces.

Infiltration Trenches
Infiltration trenches are often used in place of other BMPs where limited land is available. Infiltration trenches are most widely used in warmer, less arid regions of the U.S. However, recent studies conducted in Maryland and New Jersey on trench performance and operation and maintenance have demonstrated the appli-cability of infiltration trenches in colder climates if surface icing is avoided (Lindsey et al, 1991).

An additional limitation on use of infiltration trenches is the climate. In cold climates, the trench surface may freeze, thereby preventing the runoff from entering the trench and allowing the untreated runoff to enter surface water. The surround-ing soils may also freeze, reducing infiltration into the soils and groundwater. However, recent studies indicate that if properly designed and maintained, infil-tration trenches can operate effectively in colder climates. By keeping the trench surface free of compacted snow and ice, and by ensuring that part of the trench is constructed below the frost line, the performance of the infiltration trench during cold weather will be greatly improved.

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