This memorandum announces the public availability of the REServoir SEDimentation (RESSED) interactive website and database, available at: .

The RESSED website was developed under the auspices of the Subcommittee on Sedimentation (SOS), U.S. Water Information Coordination Program’s Advisory Committee on Water Information, through a collaborative effort among David W. Stewart, Karen T. Ray, Gregory E. Schwarz, and John R. Gray of the U.S. Geological Survey (USGS), and Jerry M. Bernard of the Natural Resources Conservation Service (formerly the Soil Conservation Service, SCS). The RESSED database used the revised, static Reservoir Sediment Survey Information System database (RESIS-II) developed primarily by the USGS National Research Program as its base. RESIS-II, in turn, emanated from the original RESIS database developed by the SCS, which aggregated data from individual datasheets (Form SCS-34). The two-page paper Form SCS-34 contains fields for entry of location and selected reservoir attributes from which a capacity-change rate could be determined given at least two surveys for a reservoir. The SOS disseminated these survey datasheets to its members starting in 1953 as part of its effort to coordinate and collect reservoir sedimentation-survey data.

The RESSED website contains:

As of June, 2009, the dynamic RESSED relational database contained results from 6,616 surveys at 1,823 reservoirs in the conterminous U.S. and two surveys at one reservoir in Puerto Rico (figure 1). These data span the period 1755-1993, with 95 percent of the surveys conducted between 1930-90 (figure 2). Reservoir surface areas range from sub-hectare-scale farm ponds to 658-square-kilometer Lake Powell. Many RESSED reservoirs are cross-referenced to the U.S. Army Corps of Engineers National Inventory of Dams (NID) and are also linked to the U.S. Environmental Protection Agency and USGS National Hydrography Datasets (NHD).

The RESSED website was developed with two primary goals in mind:

  1. make this valuable dataset readily and widely available for use in local, state, regional, and national assessments of changes in storage characteristics of selected reservoirs, and
  2. enable expansion and enhancement of the RESSED database, through:

Efforts are underway to develop a web-based data entry and update program to assist in the entry of survey data in Form SCS-34 format. If this effort is successful, revised and new reservoir-survey and ancillary data will be solicited and stored in a temporary RESSED database for subsequent quality-assuring by the SOS and refreshment of the public RESSED database.

The SOS’s RESSED workgroup, in consultation with the Office of Surface Water, believes that the current RESSED database structure requires upgrading to accommodate the new types of reservoir-survey data being produced in the 21st century. The RESSED workgroup plans to facilitate development of an enhanced reservoir sedimentation database structure capable of storing all relevant information from modern sedimentation-survey data for the Nation. Until then, the SOS will continue to capture reservoir metadata and endeavor to develop a data-entry and update program for Form SCS-34 data to enable more efficient updating of the current RESSED database.


Steve Blanchard 703-648-5629
Chief, Office of Surface Water 703-648-6693 (FAX)
Delaware River Master 571-216-1423 (Cell)
U.S. Geological Survey  
National Center, MS 415  
12201 Sunrise Valley Drive  
Reston VA 20192

Figures 1 and 2