Systems and methods for performing an aerial hydrological-assay of a topographical site require the use of an Unmanned Aerial System (UAS) for collecting image data of the site. Included in a system for the present invention is a ground-based soil moisture sensor for collecting moisture data at the site. A computer is then used to combine the image data and the moisture data to create an assay report on hydrological conditions at the site. The assay report is used to implement a water conservation plan for the topographical site which efficiently and efficaciously controls water usage at the site.