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William F. Coon

Publications and source records attributed to William F. Coon.

26 records · Page 2Linked to original sources

Simulating land-use changes and stormwater-detention basins and evaluating their effect on peak streamflows and stream-water quality in Irondequoit Creek basin, New York—A user's manual for HSPF and GenScn

A computer model of hydrologic and water-quality processes of the Irondequoit Creek basin in Monroe and Ontario Counties, N.Y., was developed during 2000-02 to enable water-resources managers to simulate the effects of future development and stormwater-detention basins on peak flows and water quality of Irondequoit Creek and its tributaries. The model was developed with the program Hydrological Simulation Program-Fortran (HSPF) such that proposed or hypothetical land-use changes and instream stormwater-detention basins could be simulated, and their effects on peak flows and loads of total suspended solids, total phosphorus, ammonia-plus-organic nitrogen, and nitrate-plus-nitrite nitrogen could be analyzed, through an interactive computer program known as Generation and Analysis of Model Simulation Scenarios for Watersheds (GenScn). This report is a user's manual written to guide the Irondequoit Creek Watershed Collaborative in (1) the creation of land-use and flow-detention scenarios for simulation by the HSPF model, and (2) the use of GenScn to analyze the results of these simulations. These analyses can, in turn, aid the group in making basin-wide water-resources-management decisions.

Open-File Report↗

Simulation of a valley-fill aquifer system to delineate flow paths, contributing areas, and traveltime to wellfields in southwestern Broome County, New York

A valley-fill aquifer system that extends along a 14-mile reach of the Susquehanna River valley in southwestern Broome County, N.Y., is a major source of water supply to local municipalities and industries, but is highly susceptible to contamination from human activities. Protection of ground-water supplies requires accurate delineation of the areas that are the sources of water pumped by wells. A previously developed two-layer steady-state ground-water flow model of the aquifer system was upgraded with an improved method of simulating stream-aquifer interactions, then recalibrated and coupled to a particle-tracking program. Three-dimensional, ground-water flow modeling coupled with particle tracking is the most reliable method of simulating groundwater flow paths in multiaquifer systems such as this; it also allows delineation of contributing areas to well.elds. A primary advantage of three-dimensional particle-tracking analysis is that it shows the complexities of the flow paths in each aquifer. Model and particle tracking analyses indicate that groundwater frequently follows convoluted three-dimensional flow paths. The contributing areas of individual supply wells in this aquifer system each has a unique flow pattern and shape. Results of the model simulation indicate that recharge from precipitation, rivers, and tributaries contribute 35 percent, 29 percent, and 25 percent, respectively to the aquifer system and that pumpage from supply wells accounts for 67 percent of the discharge from the aquifer system. Particle-tracking results indicate that the simulated contributing areas to the 24 supply wells includes most of the valley floor.

New York↗

Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

A 6-year (1990-96) study of the Ellison Park wetland, a 423-acre, predominantly cattail ( Typha glauca ) marsh in Monroe County, N.Y., was conducted to document the effect that this wetland has on the water quality of Irondequoit Creek, which flows through it. Irondequoit Creek drains 151 square miles of mostly urban and suburban land and is the main tributary to Irondequoit Bay on Lake Ontario. The wetland was a sink for total phosphorus and total suspended solids (28 and 47 percent removal efficiencies, respectively, over the 6-year study period). Sedimentation and vegetative filtration appear to be the primary mechanisms for the decrease in loads of these constituents. Total nitrogen loads were decreased slightly by the wetland; removal efficiencies for ammonia-plus-organic nitrogen and nitrate-plus-nitrite were 6 and 3 percent, respectively. The proportions of total phosphorus and total nitrogen constituents were altered by the wetland. Orthophosphate and ammonia nitrogen were generated within the wetland and represented 12 percent of the total phosphorus output load and 1.8 percent of total nitrogen output load, respectively. Conservative chemicals, such as chloride and sulfate, were littleaffected by the wetland. Concentrations of zinc, lead, and cadmium showed statistically significant decreases, which are attributed to sedimentation and filtration of sediment and organic matter to which these elements adsorb. Sediment samples from open-water depositional areas in the wetland contained high concentrations of (1) trace metals, including barium, manganese, strontium, zinc (each of which exceeded 200 parts per million), as well as chromium, copper, lead, and vanadium, and (2) some polycyclic aromatic hydrocarbons. Persistent organochlorine pesticides, such as chlordane, dieldrin, DDT and its degradation products (DDD and DDE), and polychlorinated biphenyls (PCB's), also were detected, but concentrations of these compounds were within the ranges often found in depositional environments in highly urbanized areas. Cattail shoots attained a maximum height of 350 centimeters, a density of more than 30 shoots per square meter, and total biomass of more than 5,600 grams per square meter (46 percent of which was in above-ground tissues during the growing season). Nitrogen and potassium were three times more abundant in above-ground tissues (2.4 and 1.5 percent by dry weight, respectively) than in below-ground tissues (0.8 and 0.5 percent, respectively). Concentrations of phosphorus, molybdenum, and manganese in above-ground tissues were similar to those in below-ground tissues, but the concentrations of all other constituents were considerably higher in below-ground tissues. Concentrations of several elements exceeded those typically found in natural wetlands; these included manganese (417 ppm, parts per million) and sodium (3,600 ppm) in above-ground tissues, and aluminum (1,540 ppm), iron (15,400 ppm), manganese (433 ppm), and sodium (10,000 ppm) in below-ground tissues. Large quantities of nutrients are assimilated by wetland vegetation during the growing season, but neither tissue production nor microbial metabolic processes appeared to play a significant role in the observed patterns of surface-water chemical input-to-output relations on a seasonal basis. Presumably, internal cycling of nutrients sequestered in the sediments and detritus, combined with a summer increase in microbially mediated chemical transformations, obscured the effects of vegetative assimilation during the summer on surface-water chemical loads. Additionally, the natural confinement of most flows within the banks of Irondequoit Creek, which resulted in passage of stormwater through the wetland with little dispersion or detention in the cattail and backwater areas, diminished the capability of the wetland to improve water quality. Additional factors that probably affected the chemical-removal efficiency of the wetland included chemical inflow loading rates, storage and release mechanisms of the sediments (sedimentation, adsorption, filtration, precipitaton, dissolution, and resuspension), and accretion and burial of organic matter. Measurements of chlorophyll_ a concentrations, and calculations of potential phosphorus concentrations, since the 1970’s indicate an improvement in the trophic state of Irondequoit Bay. Estimated average annual loads (1990-96) of selected constituents entering Irondequoit Bay indicate that, since 1980, the loads of all major forms of nitrogen have decreased, chloride loads have increased, and sulfate loads have changed little. Inputs of total phosphorus and suspended solids to the wetland have increased since 1980, possibly as a result of increased erosion by stormflows from an increasingly developed watershed. The wetland decreases the loads of these constituents, but the trends of these loads entering Irondequoit Bay cannot be reliably defined because the removal efficiencies during the two earlier study periods (1980–81 and 1984–88) are known.

Water-Resources Investigations Report↗

Hydrogeology and water quality of the Clinton Street-Ballpark Aquifer near Johnson City, New York

The Clinton Street-Ballpark aquifer, in the Susquehanna River valley in southern Broome County, N.Y., supplies drinking water to the Village of Johnson City near Binghamton. The hydrogeology and water quality of the aquifer were studied in 1994-95 to identify the source area of 1,1,1-trichloroethane, which was detected at the Johnson City Camden Street wellfield in 1991. The aquifer is generally 100 to 150 ft thick and consists primarily of ice-contact deposits of silty sand and gravel that are overlain by outwash deposits of sand and gravel. These two types of deposits are separated by lacustrine silt and clay of variable thickness into an upper and a lower layer of the aquifer. The coarse deposits form a single aquifer in areas where the lacustrine deposits are absent. Synoptic water-level surveys indicated that ground water moves from upgradient areas flanking the aquifer boundaries toward two major pumping centers?the Anitec wellfield in Binghamton and the Camden Street wellfield in Johnson City. Areas contributing recharge to municipal and industrial wells in the aquifer were delineated by a previously developed groundwater- flow model. The residence time of ground water within the area contributing recharge to Johnson City well no. 2 in the Camden Street wellfield was estimated to be less than 6 years. 1,1,1-Trichloroethane, trichloroethene, and their metabolites were detected in ground water at several locations in and near Johnson City. Relatively high concentrations of 1,1,1-trichloroethane were found in ground water about 3,000 ft north of the Camden Street wellfield. The suspected source is an area bordered on the south by Field Street, on the north by Harry L. Drive, on the east by New York State Route 201, and on the west by Marie Street. A trichloroethene metabolite, cis-1,2-dichloroethene, appears to be migrating westward from U.S. Air Force Plant 59 toward the Camden Street well-field, 1,000 ft southwest of the plant, although this compound has not been detected in water pumped by municipal wells, possibly because it has become diluted by ground water from other locations within the contributing area to the wells.

Open-File Report↗

Estimation of roughness coefficients for natural stream channels with vegetated banks

Roughness coefficients for 21 stream sites in New York state are presented. The site-specific relation between roughness coefficent and flow depth varies in a predictable manner, depending on energy gradient, relative smoothness (Rd50), and channel-vegetation density. The percentage of wetted perimeter that is vegetated is a useful indicator of when streambank vegetation can affect the roughness coefficient. To estimate the magnitude of this effect requires evaluation of the density and percent of submergence of vegetation.

Water Supply Paper↗

Roughness coefficients for high-gradient channels in New York State

Manning's roughness coefficients (n values) were computed for a range of flows at six streams in New York State (USA) that have high energy gradients (greater than 0.002) and large median bed-particle sizes (between 0.14 and 0.36 meters). The coefficients, which ranged from 0.034 to 0.061 for bankfull flows, were computed from discharges, channel geometry, and water-surface profiles measured at each of the sites. An inverse relation between the n values and flow depth (or hydraulic radius) was evident at five sites. The roughness coefficient decreases rapidly with increasing depth and approaches an asymptotic value as bankfull flow is approached. At individual sites, the slope (water-surface slope and energy gradient) generally increases with increasing flow depth and is inversely related to the n value. Among the sites, however, the roughness coefficient and slope show a direct relation. The near-bankfull n values on channels with slopes between 0.008 and 0.014 were generally in the range of 0.05 to 0.06, whereas those on channels with lower slopes, between 0.004 and 0.005, were in the 0.03-to-0.04 range. Streambank vegetation has a measurable effect on the computed n values at two of the sites. Dense vegetation on one side of the medium-flow channel on Beaver Kill at Cooks Falls interrupts the decreasing trend in the roughness coefficient as the water level rises and produces higher-than-expected n values up to the point of vegetation submergence. The effects of streambank vegetation at Tremper Kill near Andes change seasonally; the n-value increases by as much as 0.012 from nongrowing to growing seasons. The effect of the vegetation decreases with increasing flow depth as a result of the decrease in energy losses as the vegetation becomes submerged and bends with the flow. Roughness coefficients, which were computed around 1950 for three of the study sites, are reasonably close to those computed in this study.

Conference Paper↗

Design of Manning's-roughness-coefficient study in New York State

Field-collected hydraulic data can be used to compute roughness coefficients for channels with different hydraulic characteristics. Suggested criteria for the design of a roughness-coefficient study include: (1) location of the study reach close to an established streamflow-monitoring site with a stable high-flow stage-to-discharge relation; (2) uniform hydraulic conditions within, and upstream and downstream from, the study reach; (3) selection of at least three cross sections within the study reach that reflect the average size and shape of the channel; (4) use of peak-stage recorders at each cross section to record the maximum elevation of the water surface for a given high flow; (5) measurement of streambed particle sizes and computation of characteristic diameters, such as d50 and d84; (6) record of major flow-retarding factors (obstructions, vegetation, or frequent changes in channel size or shape) within the study reach that could cause additional energy losses beyond those resulting from the bed and bank materials alone; (7) documentation of channel conditions with photographs; (8) computation of the n value through a computer program developed for this purpose; and (9) analysis of the data from each site to determine trends and changes in the n value with flow depth and to identify discrepancies in the computed n values resulting from measurement error or violations of the assumptions on which the computational method is based.

Conference Paper↗