The conversion of pervious cover to impervious cover increases stormwater runoff and thus, stormwater pollution into our creeks, rivers and streams resulting in impaired or degraded water quality. Low Impact Development (LID) and Living Shorelines are effective best management practices for decreasing stormwater pollution and erosion. Increased population is associated with increased impervious surfaces (rooftops, parking lots, decks, etc.) as the development of land is required with increased population growth.
This project focuses on waterbodies in the Lower Cape Fear River and the adjacent population within Brunswick County. Brunswick County has seen considerable population growth and an increase in impervious surfaces and, in turn, increased degradation of water quality and closed shellfishing areas. This project attempts to find a correlation between increased population and water quality.
A New File Geodatabase was opened in ArcCatalog and appropriately named. The 2012 Impaired Water Quality dataset was downloaded from NCDEQ and the 2016 Impaired Water Quality dataset was downloaded from the USEPA both of which contain data from the entire State. Each dataset required a “select by attributes” function to capture only the impaired water from the Cape Fear River Basin. A new shapefile was created for each year 2012 and 2016. Both of these shapefiles were then clipped to the Brunswick County Block Group shapefile layer that was downloaded from the US Census Bureau.
US Census Block Group Population data downloaded from American Fact Finder for the years 2012 and 2015 were downloaded to an Excel spreadsheet and saved as an Excel workbook. It was necessary to prepare the spreadsheet for use in ArcMap (ESRI) which included deleting spaces and periods in the headings and changing the formatting for each column to “delineate” – “comma”, and then changing each column from “general” to “text”. Proper headings were entered for the columns. The spreadsheet was then imported to ArcMap. Once the table was in ArcMap, it was then joined to the Brunswick County shapefile using the GEOID and ID2 as the common key for the join. “Total Population” was the field used to symbolize population data for the block groups in ArcMap.