STATEMENT FOR INTER-AGENCY STREAM DISTURBANCE SYMPOSIUM W. C. Griffin U. S. Geological Survey The U. S. Geological Survey is a bureau in the Department of the Interior having as its principal responsibilities the evaluation and inventory of the mineral resources of the Nation. The Survey's responsibilities are carried out by four operating Divisions - Topographic, Geologic, Conservation, and Water Resources the last named being the one of which we are a part. Our function in the field of water resources investigations is somewhat unique in that we are not an action agency. We collect and analyze data, make interpretative studies, and publish results, but we do not design and execute water projects or have enforcement responsibility. Thus, we do not have water "problems" in the same sense as other agencies represented at this meeting, but we do have an interest in these discussions to the extent that they shed light on the behavior of streams as affected by the dynamic forces of nature and the works of man. Furthermore, we may get some clues here that will be useful to us in designing future programs of water resources investigations. Although the program of our West Virginia District is a part of the National activity, we do have some flexibility in tailoring it to meet local needs. As some of you know, a part of our funding comes from Federal-State matching and the Division of Water Resources of your Department of Natural Resources is a leading State cooperator. Stream sedimentation is by no means as severe a problem in West Virginia as it is in the southwestern part of the Country, for example, but as has been brought out in earlier presentations here sedimentation problems do exist in this State. We have collected some sediment data as a part of water resource investigations projects carried on in some basins, such as the Potomac, the Monongahela, and the Little Kanawha, but all in all we know very little about sediment characteristics of West Virginia streams. In making a start at overcoming this deficiency, we have recently begun collecting sediment samples at 11 stream-gauging stations as a reconnaissance activity. We collect about 10 water-sediment samples a year and send them to the U.S. G. S. Laboratory in Columbus, Ohio for analysis of concentration and for occasional particle-size analysis. In picking our sampling stations, we did not seek problem streams. Rather, our aim was to learn something about natural sedimentation characteristics throughout the State in order to develop reference information for possible investigations later on in problem areas. However, as we picked stations having a few hundred square miles of drainage area it is inevitable that man-induced sedimentation cannot be avoided entirely. 62-365 71 pt. 3 - 22 Determination of sediment load in tons per day would require more intensive effort than I have described. With daily samples and water discharge data such determinations could be made, and in fact have been made for short periods on some streams in the State. If such investigations are justified on any of your "problem" streams, we could look into the possibility of some kind of cooperative effort to obtain information on the scope of the problem. The next part of our presentation will be given by Mr. Glenn Wyrick, the Assistant Chief of our West Virginia District. He is a hydrologist with wide experience in ground-water investigations and he will talk about interrelationships between ground water and stream flow. STATEMENT BY MR. WYRICK The discussion of the effects on water resources of artificial changes in streams should be preceded by a brief discussion of the hydrologic cycle. In the hydrologic cycle, water is evaporated from a body of water, such as a lake, stream or ocean, and carried by the atmosphere until it condenses and precipitates. Of the precipitation that falls on land surface, a part runs off overland to streams and the oceans, a part percolates to the water table to become ground water and, under the influence of gravity, drains to streams and the oceans and a part is evaporated on or near land surface or is used by vegetation and is transpired back to the atmosphere (evapotranspiration). Any change in any one of the parameters, that is, a change in atmospheric, streamflow, ground-water, or evaportranspiration conditions affects all of the other conditions. The most widely known example of this is the effect of a drought (a decrease in precipitation due to changes in atmospheric conditions) which decreases or eliminates stream flow, lowers ground-water levels and reduces evapotranspiration. Similarly, a change in streamflow characteristics changes all of the other parameters to some degree. The relationship between streamflow characteristics and ground-water characteristics is of primary concern because streams and aquifers are the principal sources of water supply for mankind and because these two sources are most susceptible to manmade changes. Where water levels in streams are higher than the local water table, water is lost from the streams to the water-table aquifer. Where the water level in the adjacent aquifers is higher, water is lost from the aquifers to the streams. In this State the water table is generally higher than the surface of streams and water moves from the aquifers to the streams, maintaining streamflow during periods of low precipitation and low surface runoff. Two types of changes may be made in streams which affect the flow characteristics of the stream and affect ground-water conditions. The levels of streams may be lowered by various types of channel improvement or the stream levels may be raised by various types of impoundment. In either case, there is a corresponding change in nearby ground-water storage and flow characteristics. Where channels are cleared, dredged or straightened, the water level of the stream is usually lowered and, in time, the water table is lowered in the vicinity of the stream. This may result in a reduction of swamp areas and a reduction of ground-water in storage to maintain base flow in the stream during drought. Where impoundments are constructed, the water level in streams rise and, in time, the adjacent water table also rises as ground-water storage increases. This may result in the creation of swamp areas and it may also provide more water for base flow in the stream during drought periods. The determination of the benefits from a particular project must be made on an individual site basis. For example, would the elimination of swamps by channel improvement be a benefit in a wildlife area? Most likely not, but it probably would be a definite benefit in an industrial area. Would the effects of an impoundment, such as one proposed in Greenbrier County, which conceivably would cause new springs to form near White Sulphur, be a benefit? As this area is a resort area, dependent partially on the attraction of existing springs, it probably would be a benefit unless the present springs become less mineralized. The point is that any artificial change in a stream's characteristics will cause changes in the other parameters. Especially the ground-water parameter and, thus, the water-related land will be changed in ways which may not be immediately apparent. Therefore, the benefit from a given project must be assessed in terms of the immediately apparent and obvious benefits and, also, in terms of the effects on the other hydrologic parameters which may not be obvious or immediately apparent. CONCLUDING ROUND-TABLE DISCUSSION The Wednesday morning session was chaired by Mr. Peter Zurbuch, Chief of the Game and Fish Division, and devoted to a round-table discussion by all participants on possible procedures and solutions to the stream disturbance problem. A task force committee was ultimately formed, consisting of representation from state and federal agencies. The basic objective of the task force was to develop meaningful memorandums of understanding between the Department of Natural Resources and other agencies, that would establish review procedures for projects adversely effecting stream resources, and to insure continued inter-agency understanding and cooperation in dealing with such projects. ATTENDANCE LIST Clifford Benoit, U. S. Forest Service J. D. Brackenrich, Department of Natural Resources Ed Johnson, Department of Natural Resources C. W. McIntyre, U. S. Army Corps of Engineers Allen J. Miller, Agricultural Stabilization and Helen Morris, Department of Natural Resources T. R. Samsell, Department of Natural Resources |