Get News Feed
People in the Urban Environment
Urban or built-up environments are comprised of areas of intensive use with much of the land covered by impervious surfaces such as structures, parking lots, and roads. Included in this category are cities and towns, transportation networks such as highways and railways, power and communications facilities, and areas such as shopping centers, industrial and commercial complexes, institutions, agricultural processing facilities, and commercial complexes, institutions, acgricultural processing facilities, and rural residential areas.
In Napa County, urban and built-up areas make up over 21,000 acres (California Dept of Conservation, Division of Land Resources Protection, 2003). While built-up areas in Napa County only make up about 4% of the landscape, their effect on the health of the watershed is significant. One of the main concerns is the amount of impervious surfaces added to the landscape. Impervious surfaces, including parking lots and rooftops, prevent rainwater from soaking into the ground. If these surfaces stood alone in a sea of porous soil and vegetation, they would not cause many problems, but in the urban environment they are connected to each other. Rooftops drain onto driveways and sidewalks that connect to a network of paved streets. During rain storms, these surfaces channel water into storm drains which then discharge the water (and pollutants picked up along the way) directly into our waterways. Streams in urban areas fill faster (since water runs off pavement quickly) and with more water than their natural counterparts. The result is greater stream channel erosion and increased flood events. Slowing the movement of water and preventing water pollution are two major challenges in our urban areas. Installing storm water detention devices, replanting stream banks, adopting measures to decrease sedimentation from construction sites, and educating the public about storm drain pollution are some of the strategies being used to alleviate the problem.
Source: Napa County Resource Conservation District
Photo by Todd Adams
