Stormwater-Pavement Interface in Cold Climates

Abstract

This project relates to “managing stormwater runoff in cold climates” and addresses the feasibility of low-impact development at a regional demonstration site in eastern Washington. The studies relate to seven large permeable pavement systems. The findings for similar climates and soils are as follows:

 The draindown times for retention in Palouse or similar clay soils may handle many typical storms.

 On average, every square foot of a permeable pavement system installed also receives run-on from another square foot of impermeable pavement, doubling its impact on both stormwater quantity reduction and stormwater quality improvement.

 Most of the clogged sections on various applications were downslope of other areas.

 Permeable pavements installed in areas targeted for additional stormwater quantity control and quality improvement may be feasible.

 On average, the cleaning for installations is less frequent than annually. Power washing plus vacuuming appears to be an effective method for pervious concrete.

 Surface distress was usually where vehicles turned, or from placement activities.

 Preliminary studies on various surface treatments on pervious concrete show promise for added safety benefits under wintry conditions.

 Both detention-type and retention-type permeable pavement systems appear to have little negative impact on neighboring soils in the winter under the study conditions. However, further research is needed for different designs of retention-type systems to ensure that water volumes in the aggregate storage bed do not allow for sufficient water flow into neighboring soils that might result in ice lens formation or other negative impacts.