The Delaware DataMIL, an online web mapping application that has provided accurate, up-to-date Delaware Geospatial Framework (basemap layers), current and historic aerial photography, and topographic maps for Delaware since 2002 is retired as of June 30, 2013. Originally built as a state of the art, crowd source editing and map delivery system and pilot project for the US Geological Survey National Map, the DataMIL is being replaced by newer mapping technology through the Department of Technology and Information (DTI) which will have a new system in place shortly.
The Delaware Geological Survey (DGS) has measured, managed, and distributed groundwaterlevel data for several decades using widely accepted procedures and practices, many of which were derived from interactions with staff of the USGS, consulting firms, and other state agencies. Many of the individual methods and procedures have been described in DGS reports, however, written documentation for these tasks have not been assembled in a single published document.
In 2015, staff of the Water Supply Section of the Delaware Department of Natural Resources and Environmental Control (DNREC) informed the DGS of their concerns about overpumping of the unconfined Columbia aquifer in an area east of Dover (Figure 1). In this area, the City of Dover’s Long Point Road Wellfield (LPRW) and numerous irrigation systems pump water from the shallow Columbia aquifer.
The DGS has been a data provider for the National Ground-Water Monitoring Network (NGWMN) since 2016. NGWMN is a consortium of state and local agencies and the U.S.
A parameterization of tidal marsh inundation was developed for the 1,200 hectares of tidal marsh along the 12-km reach of the tidal Murderkill River between Frederica and Bowers Beach in Kent County, Delaware. A parsimonious modeling approach was used that bridges the gap between the simple and often used “bathtub model” (instantaneous inundation based on tides in Delaware Bay), and the more complex modeling of shallow overland that results in the wetting and drying of tidal marshes.
The geological history of the surficial units of the Clayton, Smyrna, and the Delaware portion of the Millington Quadrangles are the result of deposition of the Beaverdam Formation and its modification by erosion and deposition of the Columbia Formation during the early Pleistocene. These units were then modified by the Lynch Heights and Scotts Corners Formations as a result of sea-level fluctuations during the middle to late Pleistocene. The geology is further complicated by periglacial activity that produced Carolina Bay deposits in the map area, which modified the land surface.