A River Runs Through It: Stormwater Design at VMI, Part 2

If you haven’t read Part 1 of this post yet, read here.

The project site for the Corps Physical Training Facility at VMI presented the design team with a unique stormwater design challenge, which allowed for several creative solutions to minimize the stormwater impact of construction. The development of the site converted an area that had previously been mostly open space into a highly developed site, which without proper stormwater controls would cause a substantial increase in runoff as well as water-borne pollutants. To mitigate this, the project included installation of many stormwater practices including: bioretention, a green roof, permeable pavement, underground detention, a rainwater harvesting system, and several manufactured BMPs.

Green roof

 

Construction of traditional bioretention was a particular challenge because of steep slopes on the site. The project team’s solution was to design and construct a “stepped” bioretention basin, where water would flow into the top of four terraces before overflowing through the lower basins and ultimately running into the Town Branch after it had been filtered.

Stepped bioretention basin

 

Another unique stormwater solution was the integration of rainwater harvesting and underground detention below a planting bed in front of the building. Water from the roof first flows into the rainwater harvesting portion of the structure, where it is collected for use within the building and the cooling system. When a larger storm occurs, the water flows into a second chamber in the underground system where it is detained and released slowly into the creek. The design was based off of standard VDOT box culverts to avoid the need for a completely custom structure.

Rainwater harvesting below planting bed

 

Have questions about this project or other stormwater related work? Contact Carolyn Howard.