Watershed Summary:

(Last edited on Oct. 8, 2015)

The Webb Branch is part of Stroubles Creek located in Montgomery County, Virginia, USA (Figure 1). The Webb Branch watershed is unusual in that it is a small urban watershed (2.78 km2, 95% Urban land use) that drains through farmland and forest before reaching the New River, and eventually reaching the Gulf of Mexico via the Mississippi River. Just downstream from the Learning Enhanced Watershed Assessment System (LEWAS) field site (37.22818 deg N, 80.42705 deg W) where the data is collected, the Webb branch drains into the Upper Duck Pond on the Virginia Tech campus in the town of Blacksburg, Virginia, USA. The urban environment has a detrimental impact on Stroubles Creek. The first 8 km of Stroubles Creek below the Lower Duck Pond has been classified as benthically impaired in all Virginia Department of Environmental Quality (VDEQ) reports from 1996 to the present. Some of the factors stressing this section of Stroubles Creek are increased development in the watershed, urban pollution entering the stream (Figure 2), increased amounts of sediment entering the stream and modifications to the stream channel.

Stroubles Creek Watershed
Figure 1. Webb Branch Watershed in Stroubles Creek Watershed.

Debris at the LEWAS field site
Figure 2. A selection of the debris found at the LEWAS field site including the back of an iPhone case, shotgun shells, a hubcap, the jawbone of a small animal, a “no dumping” sign, the head of a plastic goose, a sandal, a gas cap, a plastic monkey, fast food packaging, a WD-40 can, a snack cracker package, a soccer ball, beverage cans, golf balls, a credit card, a “private property” sign and a bag from ice melt.

The relatively small drainage area coupled with the high percentage of impervious surfaces within the watershed result in a relatively high peak discharge rate of relatively short duration, i.e. the stream responds to events quickly and returns to base flow conditions quickly. This can be seen in the example event in Figure 3.

Plot of thunderstorm parameters
Figure 3. July 2012 Thunderstorms result in rapid transitions in stream conditions.

References:
1) Virginia Department of Environmental Quality (VDEQ), 2006. Upper Stroubles Creek Watershed TMDL Implementation Plan Montgomery County, Virginia. VT-BSE Document No. 2005-0013, Blacksburg, Virginia.
2) Virginia Department of Environmental Quality (VDEQ), 2012. 305(b)/303(d) Water Quality Assessment Integrated Report. Richmond, VA.