This tool begins by importing the latest available data from WPDx for the given district. Next, it imports high resolution population maps of the district from ESRI’s Living Atlas. This provides an estimate of the number of people living within every 250m x 250m grid square in the district. The tool then draws a circle around all water points with a radius equal to the access distance provided. The value of the population grid squares within the access circle are set to 0, as all of the people within the access distance of a water point could potentially have water access using existing infrastructure. The tool then draws a circle around the center of every 250m x 250m with a radius equal to the access distance provided and adds up the total population of all grid squares within the circle. All possible locations are ranked based on the population that could be served, and the data is provided for the top locations, based on the number of candidates provided.
This analysis is based on the latest available data, and population estimates from ESRI. Any water points that have been broken, rehabilitated, or constructed for which the data is not in WPDx have not been included in this analysis. Additionally, household connections are not captured in WPDx. While large urban areas are removed from the analysis if they reach a specified population density, smaller piped schemes with household connections may be missed. As a result, peri-urban areas may be identified as optimal locations, even if those communities are already served by household connections.