Current design recommendations for regulating temperature in urban stormwater BMPs can be found in the Urban Waterways publication, Stormwater BMPs for Trout Waters.

Design Guidance Summary

Bioretention Area

Soil Depth

• Install drains at a depth of 3 ft or greater

Vegetation

• Keep soil well shaded using broad leaf vegetation with a separation between the leaves and soil surface

Mulch

• Use light-colored mulch

Drainage Configuration

• Incorporate an internal water storage (IWS) layer at the bottom of the bioretention media. The top of the IWS layer should be at least 3 ft from the soil media surface

Stormwater Wetland

Outlet Structure

• Draw water from the bottom of the deep pool at the wetland's outlet
• Aerate water before discharging into stream
• Limit outflow rates early in a storm

Vegetation

• Keep water well shaded using broadleaf vegetation with a separation between the leaves and water surface

Wet Pond

Outlet Structure

• Draw water from the bottom of the deep pool at the wet pond's outlet
• Aerate water before discharging into stream
• Limit outflow rates early in a storm