George Washington Regional Commission and Urban Heat Islands

In 1968 under the Regional Cooperation Act , Virginia was divided into planning districts based on the proximity and common interests among its counties, cities and towns. There are 21 regional commissions in Virginia. They are made up of elected officials and citizens appointed to the Commission by the member local governments. The Commission selects an Executive Director responsible for managing daily operations and has staff. Commission offices are located generally in a central location for the region as determined by the Commission charter. 

We in Prince William are part of the Northern Virginia Regional Commission that consists of Fairfax, Arlington, Prince William and Loudoun along with their independent cities and incorporated towns in these counties. Adjacent to the eastern part of Prince William County  is the George Washington Regional Commission which encompasses; Caroline County, City of Fredericksburg, King George County, Spotsylvania County, and Stafford County.

At the last Potomac Watershed Roundtable meeting, Meredith Keppel, the Environmental Planner at the George Washington Regional commission told us about some of their environmental work. Their region has several ongoing environmental programs intended to help the region use land wisely. Some of these programs are a septic relief program that pulls together various resources and funding to facilitate septic repairs for citizens. A native plant campaign and funding sources for the Chesapeake Bay Watershed Implementation Plan funding sources. However, the program with the most fascinating story was the Green Infrastructure program.

The George Washington Regional Commission is hosting a Green Infrastructure charette to “collaboratively explore and envision how green infrastructure can address stormwater and urban heat island issues in the region.” This charette will take place on  Friday, April 26, 2024 starting at noon at the Howell Library Branch in Fredericksburg, VA. You can got to the GW Commission website for more information. https://gwregion.org/environment/green-infrastructure

One of the best definitions I’ve seen of green infrastructure comes from the American Rivers Association What is Green Infrastructure? (americanrivers.org) edited below:

Green infrastructure is an approach to water management that protects, restores, or mimics the natural water cycle. Green infrastructure means planting trees and restoring wetlands, choosing water efficiency, instead of building more water supply dams, restoring floodplains instead of building taller levees. Green infrastructure incorporates both the natural environment and engineered systems to provide clean water, conserve ecosystem functions, and provide a wide array of benefits to people and wildlife.

Green infrastructure solutions can be applied on different scales. On the local level, green infrastructure practices include rain gardens, permeable pavements, green roofs, infiltration planters, trees, and tree boxes, and rainwater harvesting systems. At the largest scale, the preservation and restoration of natural landscapes (such as forests, floodplains, and wetlands) are critical components of green infrastructure.

In its simplest terms green infrastructure is changing the way you live and build to capture rainwater where it falls and allowing it to absorb into the earth or be taken up by plants. Plants use the sun's energy and do not reflect it back. What is really interesting about this program at the George Washington Regional commission is its origin. The green infrastructure is intended to address flooding and the urban heat island effect.

Areas with a large amount of impervious surfaces (such as asphalt, concrete, buildings, etc.) not only are susceptible to flooding but are also susceptible to  higher ambient air temperatures because the man made roads, parking lots, concrete surfaces and buildings absorb and trap heat more heat than natural environments. Plants use the energy of the sun while man made surfaces absorb and radiate the energy of the sun. These clustering of heat absorbing manmade surfaces and structures create Urban Heat Islands that can impact a community’s environment and quality of life increasing energy consumption for cooling, increase emissions of air pollutants and greenhouse gases, and impaired water quality.

Friends of the Rappahannock conducted a study of ambient temperatures a couple of years ago. Using  volunteers who obtained 320 air temperature measurements at 20 sample sites within the George Washington Region on July 10, 2022. These samples were then put into a Random Forest model in ArcGIS Pro (an ESRI product). The model was used to extrapolate temperatures across the region, ultimately identifying non-heat islands, heat islands, and urban heat islands. The data found that 3.57% of the landmass of the region (approximately 32,700 acres) was an EPA classified urban heat island.

 Geographically the heat island results were clustered in Fredericksburg and surrounding areas into Stafford and Spotsylvania. An area in north Stafford recorded the highest temperature in the study at 104℉. This temperature was a  17-degree Fahrenheit difference from forestland temperatures found. Other hotspots included the Route 17 corridor in Stafford County; Central Park and Celebrate Virginia South in Fredericksburg; the Spotsylvania Towne Center and Cosner’s Corner in Spotsylvania County; and Dahlgren and the King George Landfill/Birchwood Power complex in King George County.

This map is from the press release 

A 17℉ heat island effect was stunning to the George Washington Regional Commission and quite frankly, me. In the hottest days of summer, there is always a cooler breeze coming from the woodland behind my home in the evenings. With all the industrial development of data centers are we building urban heat islands, too. Maybe the Northern Virginia Regional Commission should take a look at that.