Why use RAD in the beaches allotment formula?
The RAD is regularly used by national water programs to provide statistics on program features, (i.e., number of beaches, beach miles by state) that are comparable nation-wide, e.g., they have been normalized in scale, units of measure, precision, and accuracy. This means the length of a beach in the RAD may be different than the length measured by a state. However, it is equitable for all states because the normalized lengths are included in each state’s total beach miles, and presented as their percentage of the national total in the proposed allotment formula. The RAD stores the reach address of each beach or “similar point of access”, which has been linked to the underlying surface water features (ocean, estuary, lakes, etc) in the NHD. These reach addresses record the geographic location and extent of each beach or similar point of access in both tabular and spatial formats. Periodically, EPA retrieves an updated version of the NHD from USGS and migrates all reach addresses then i
