The DowntownDC Business Improvement District (BID) has undertaken a green infrastructure audit as a part of its ongoing DowntownDC ecoDistrict program to create a healthy, enjoyable and sustainable place for workers, residents, and visitors. Green spaces benefit the environment by reducing stormwater runoff, which pollutes our rivers, reducing the heat island effect and cleaning the air. The audit encompasses green features in public space and privately-owned property.
The BID has cataloged existing green spaces within its 138-block area and is now attempting to identify opportunities to create new green infrastructure as well as expand upon existing projects. The BID is asking people who live and work in downtown to help identify these green opportunities by responding to a brief, on-line survey. [See below]
Along with the environmental benefits associated with investment in green infrastructure, green spaces offer benefits to business, such as employee satisfaction. A recent study conducted by the Natural Resources Defense Council (NRDC) showed that office workers have a clear preference for nature near the workplace, which leads to improved health and job satisfaction, and in turn, leads to better staff retention and higher productivity. The addition of green infrastructure not only benefits the businesses that rent commercial space, but also property owners, who can receive increased rents from tenants who are willing to pay for these benefits.
A similar audit conducted by the Victoria BID in London in 2010 found that participation in the audit encouraged BID members to invest in urban greening and the audit corroborated the findings of the NRDC study; enhancing the natural environment improved workforce satisfaction and increased property values. The audit also identified opportunities, that when implemented, could have many positive environmental impacts. For example, the Victoria BID found that by implementing 4.2 acres of proposed projects in their area, pollutants, stormwater and hot temperatures were impacted. (See graphic below.)
Potential Benefits for Victoria BID for 4.2 Acres of Proposed Green Projects
A wide range of green elements within the BID have already been recorded in the BID staff’s audit of existing green spaces conducted earlier this spring. The audit found that within the DowntownDC BID there are 3,857 trees, which capture 185,136 pounds of carbon dioxide a year, reduce the urban heat island effect and improve air quality. The BID is also home to 27 existing green roofs (totaling 203,364 square feet) that capture stormwater and reduce building energy usage.
The BID also has some less conventional green elements. There are two beehives on the roof of 650 Massachusetts Avenue NW and a water system on the roof of D.C. Fire Department Engine Company 3 (439 New Jersey Ave NW) directs roof runoff to cisterns used to fill fire truck tanks and wash trucks.
The city and federal government offer several grants and incentives to creating these projects that can help defray costs. Putting a green roof on a building or adding a tree to an empty tree box brings D.C. one step closer to having swimmable and fishable rivers.
The green infrastructure audit hopes to not only give credit to many of the great existing projects, but to enable the expansion of green infrastructure across Downtown. Your response to the online survey will help the BID reach that goal.
Examples of green features include:
- Green Roofs: The roof of a building that is partially or completely covered with vegetation and a growing medium, planted over a waterproofing membrane. It may also include additional layers such as a root barrier and drainage mat and insulation.
- Living Walls: A wall partially or completely covered with vegetation that includes a growing medium, such as soil. Most green walls also feature an integrated water delivery system.
- Rain Gardens: A planted depression that allows rainwater runoff from impervious urban areas, like roofs, walkways, parking lots and compacted lawn areas the opportunity to be absorbed. This reduces rain runoff by allowing stormwater to soak into the ground (as opposed to flowing into storm drains and surface waters which causes erosion, water pollution, flooding and diminished groundwater).
- Parklets: A sidewalk extension that provides more space and amenities for people using the street. Usually parklets are installed on parking lanes and use several parking spaces.
- Plantings: A cultivated bed with non-competitive annuals that absorbs storm water, keeping it from running off bare, hard soil and overwhelming the sewer system.