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Hydrologic Benchmark Network Stations in the U.S. 1963-95 (USGS Circular 1173)


        In 1962, L.B. Leopold, then Chief Hydrologist of the U.S. Geological Survey (USGS), proposed to establish a network of hydrologic benchmarks to make long-term measurements of various hydrologic characteristics in areas that were free from the effects of human activities (Leopold, 1962). The main purpose of the network was to provide a long-term hydrologic data base to be used to study temporal trends in hydrologic characteristics and to serve as controls for separating natural from manmade changes in other streams. The Hydrologic Benchmark Network (HBN) was started in 1963, and sites were selected on the basis of four criteria: (1) No manmade storage, regulation, or diversion was to exist in the basin; (2) ground water in the basin was not to be affected by pumping from wells; (3) conditions were to be favorable for accurate measurement of streamflow and water quality; and (4) the potential was to be small for special natural changes, such as beaver activity, overgrazing or overbrowsing, or extensive fire (Cobb and Biesecker, 1971). Most of the stations selected for the network were located in areas virtually free of human activities, such as national parks, wilderness areas, or nature preserves. However, such undisturbed areas no longer existed in many parts of the country, and the decision was made to include basins where logging or agriculture was practiced under the assumption that stations in such basins would still yield useful information as long as the land use did not change (Lawrence, 1987). Most stations in the HBN were established by the late 1960's and, after a few changes in the 1970's and 1980's, the network eventually consisted of 57 streamflow stations and one lake-stage station in 39 States (fig. 1). Following an evaluation of the HBN program in the early 1990's, eight stations were discontinued and two stations were replaced for the following four reasons: (1) The sites were operated as discharge-only stations during the period of record (Tallulah River, Ga.; Swiftcurrent Creek, Mont.; and Little Vermillion River, S. Dak.), (2) poor discharge records were collected at the station (Honolii Stream, Hawaii, replaced by Kahakuloa Stream, Hawaii), (3) substantial changes in land use occurred during the period of record (Upper Three Runs, S.C.), or (4) water quality at the gage was strongly affected by upstream human activities (Esopus Creek, N.Y., replaced by Biscuit Brook, N.Y.; Falling Creek, Ga.; South Hogan Creek, Ind.; North Fork Whitewater River, Minn.; and Elk Creek, Iowa). Because of budgetary restrictions, water-quality sampling was decreased at all HBN stations in October 1986 and discontinued in October 1997.

        The original network design to study temporal trends was first used to test whether changes in acidic deposition from the atmosphere were causing regional trends in surface-water chemistry (Smith and Alexander, 1983). This attempt to ascribe surface-water trends to environmental changes revealed a lack of ancillary data for the HBN, particularly for precipitation quality and quantity. Because temporal trends in surface-water chemistry may exist at many of the HBN stations, it is necessary to determine whether environmental factors, such as precipitation chemistry and land use, or changes in analytical methods could have caused the observed trends. However, documentation of environmental characteristics and method-related effects is minimal for most HBN stations, and hydrologic characteristics other than stream discharge and chemistry were seldom measured. In addition, if the HBN is to be useful as a control for separating natural from manmade changes in other streams, an understanding of the natural and manmade factors that affect water quality in these basins is needed. In 1990, the USGS undertook an evaluation of the HBN program to provide detailed information for sites in the network and to determine the suitability of each site with regard to the original design criteria.

Purpose and Scope

        This report describes the environmental characteristics and water quality of 58 HBN stream basins in the United States. The following information is presented for each HBN basin: (1) An overview of the basin characteristics, including physiography, geology, soils, vegetation, land ownership, basin access, and land use; (2) an analysis of the historical water-quality records for the HBN station in each basin for the period of record through water year 1995, including data quality, water-quality characteristics, and time-series trends; and (3) an interpretation of the intrabasin variability in surface-water chemistry for selected tributary streams in each basin that were sampled between January 1991 and April 1993. This report is intended to provide a framework of information to aid in the application and interpretation of water-quality data collected as part of the HBN program.

Previous Work

        Although the HBN has been in existence for more than 30 years, only a few studies have assessed or analyzed data for the entire network. Brief descriptions of the HBN drainage basins and water-quality characteristics of the streams were compiled by Cobb and Biesecker (1971). Biesecker and Leifeste (1975) compared water-quality constituents for undisturbed HBN stations with constituents for major streams that drain similar hydrologic regions of the United States. Smith and Alexander (1983) examined time trends in pH, alkalinity, and sulfate at 47 HBN stations to investigate the long-term effects of acidic deposition on water quality in undeveloped basins. Lins (1986) used a principal-component analysis to determine whether patterns in stream sulfate at 30 stations in the network could be used as analogues for regional patterns in sulfate deposition from the atmosphere. Lawrence (1987) presented a compilation of streamflow characteristics for 58 HBN stations, including an analysis of time trends in streamflows for the period of record through water year 1980.

        Few process-level investigations have been conducted by the USGS in the individual network drainage basins. One exception is for McDonalds Branch in New Jersey, which was the site of an acidic deposition study from 1984 through 1988 (Lord and others, 1990; Johnsson and Barringer, 1993). The Biscuit Brook Basin, N.Y., which replaced the Esopus Creek Basin in 1991, has been the site of several biogeochemical investigations (Murdoch, 1991; Murdoch and Stoddard, 1993). Site-specific investigations were more limited in scope at other HBN stations. Hainly and Ritter (1986) collected samples from tributary streams in the Esopus Creek Basin, N.Y., and Young Womans Creek Basin, Pa., to determine the representativeness of water quality at the basin outlet compared to water quality in headwater areas of these basins. Several observation wells and rain gages were installed in the Holiday Creek Basin, Va., in the early 1970's to investigate rainfall-runoff relations, but the project was not completed (Edward Knuckles, U.S. Geological Survey, oral commun., 1994). Buell (1985) investigated time-series trends in water-quality constituents at Falling Creek, Ga., in order to evaluate the effects of land use on water quality in similar basins.


        The authors express their appreciation to employees of the U.S. Department of Agriculture Forest Service and Natural Resources Conservation Service (formerly the Soil Conservation Service), National Park Service, Piedmont National Wildlife Refuge, Appomattox-Buckingham State Forest, Lebanon State Forest, New York City Department of Environmental Protection, Pennsylvania Department of Environmental Resources, Pinelands Commission, Sproul State Forest, Susquehannock State Forest, and the USGS who provided information for this study. The authors also express gratitude to USGS employees Donald H. Campbell, David W. Clow, Kathleen K. Fitzgerald, George P. Ingersoll, Wendy O. Meyer, Anthony J. Ranalli, Norman E. Spahr, and Amy Swancar for technical assistance and data collection.


References Cited

Biesecker, J.E., and Leifeste, D.K., 1975, Water quality of hydrologic benchmarks—An indicator of water quality in the natural environment: U.S. Geological Survey Circular 460-E, 21 p.

Buell, G.R., 1985, The hydrologic bench-mark program-A standard to evaluate time-series trends in selected water-quality constituents for streams in Georgia: U.S. Geological Survey Water-Resources Investigations Report 84-4318, 36 p.

Cobb, E.D., and Biesecker, J.E., 1971, The National Hydrologic Benchmark Network: U.S. Geological Survey Circular 460-D, 38 p.

Hainly, R.A., and Ritter, J.R., 1986, Areal and temporal variability of selected water-quality characteristics in two hydrologic benchmark basins in the Northeastern United States: U.S. Geological Survey Water-Resources Investigations Report 85-4025, 22 p.

Lawrence, C.L., 1987, Streamflow characteristics at hydrologic benchmark stations: U.S. Geological Survey Circular 941, 123 p.

Lins, H.F., 1986, Recent patterns of sulfate variability in pristine streams: Atmospheric Environment, v. 20, no. 2, p. 367-375.

Leopold, L.B., 1962, A national network of hydrologic benchmarks: U.S. Geological Survey Circular 460-B, 4 p.

Lord, D.G., Barringer, J.L., Johnsson, P.A., Schuster, P.A., Walker, R.L., Fairchild, J.E., Sroka, B.N., and Jacobsen, Eric, 1990, Hydrogeochemical data from an acidic deposition study at McDonalds Branch basin in the New Jersey Pinelands, 1983-1986: U.S. Geological Survey Open-File Report 88-500, 124 p.

Johnsson, P.A., and Barringer, J.L., 1993, Water quality and hydrogeochemical processes in McDonalds Branch basin, New Jersey Pinelands, 1984-1988: U.S. Geological Survey Water-Resources Investigations Report 91-4081, 111 p.

Murdoch, P.S., 1991, Chemical budgets and stream-chemistry dynamics of a headwater stream in the Catskill Mountains of New York, October 1, 1983, through September 30, 1985: U.S. Geological Survey Water-Resources Investigations Report 88-4035, 66 p.

Murdoch, P.S., and Stoddard, J.L., 1993, The role of nitrate in the acidification of streams in the Catskill Mountains of New York: Water Resources Research, v. 28, no. 10, p. 2707-2720.

Smith, R.A., and Alexander, R.B., 1983, Evidence for acid-precipitation-induced trends in stream chemistry at hydrologic benchmark stations: U.S. Geological Survey Circular 910, 12 p.


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Last updated July 17, 2000.