Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Water-Resources Report”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,045 records · Page 58Linked to original sources
USGS2002

Measured and simulated runoff to the lower Charles River, Massachusetts, October 1999–September 2000

The lower Charles River, the water body between the Watertown Dam and the New Charles River Dam, is an important recreational resource for the Boston, Massachusetts, metropolitan area, but impaired water quality has affected its use. The goal of making this resource fishable and swimmable requires a better understanding of combined-sewer-overflow discharges, non-combined-sewer-overflow stormwater runoff, and constituent loads. This report documents the modeling effort used to calculate non-combined-sewer-overflow runoff to the lower Charles River. During the 2000 water year, October 1, 1999–September 30, 2000, the U.S. Geological Survey collected precipitation data at Watertown Dam and compiled data from five other precipitation gages in or near the watershed. In addition, surface-water discharge data were collected at eight sites—three relatively homogenous land-use sites, four major tributary sites, and the Charles River at Watertown Dam, which is the divide between the upper and lower watersheds. The precipitation and discharge data were used to run and calibrate Stormwater Management Models developed for the three land-use subbasins (single-family, multi-family, and commercial), and the two tributary subbasins (Laundry and Faneuil Brooks). These calibrated models were used to develop a sixth model to simulate 54 ungaged outfalls to the lower Charles River. Models developed by the U.S. Geological Survey at gaged sites were calibrated with up to 24 storms. Each model was evaluated by comparing simulated discharge against measured discharge for all storms with appreciable precipitation and reliable discharge data. The model-fit statistics indicated that the models generally were well calibrated to peak discharge and runoff volumes. The model fit of the commercial land-use subbasin was not as well calibrated compared to the other models because the measured flows appear to be affected by variable conditions not represented in the model. A separate Stormwater Management Model of the Stony Brook Subbasin previously developed by others was evaluated with the newly collected data from this study; this model had a model fit comparable to the models developed by the U.S. Geological Survey. The total annual runoff to the lower Charles River during the 2000 water year, not including contributions from combined-sewer-overflows except from the Stony Brook Subbasin, was 16,500 million cubic feet; 92 percent of the inflow was from the Charles River above Watertown Dam, 3 percent was from the Stony Brook Subbasin, 2 percent was from the Muddy River Subbasin, and less than 1 percent was from the combined inflows of Laundry and Faneuil Brooks. The remaining ungaged drainage area contributed about 2 percent of the total annual inflow to the lower Charles River. Excluding discharge from the Charles River above Watertown Dam, total annual runoff to the lower Charles River was 1,240 million cubic feet; 39 percent was from the Stony Brook Subbasin, 27 percent was from the Muddy River, which includes runoff that drains to the Muddy River conduit, 7 percent was from the Laundry Brook Subbasin, and 4 percent was from the Faneuil Brook Subbasin. Flow from the ungaged areas composed about 23 percent of the total annual inflow to the lower Charles River, excluding discharge from the Charles River above Watertown Dam. Runoff to the lower Charles River was calculated for two design storms representing a 3-month and a 1-year event, 1.84 and 2.79 inches of total rainfall, respectively. These simulated discharges were provided to the Massachusetts Water Resources Authority for use in a receiving-water model of the lower Charles River. Total storm runoff to the lower Charles River was 111 and 257 million cubic feet for the 3-month and 1-year storms, respectively. Excluding discharge from the Charles River above Watertown Dam, total runoff to the lower Charles River was 30 and 53 million cubic feet for the 3-month and 1-year storms, respectively. Runoff from the various tributary areas for the design storms was about in the same proportion as that for the annual runoff.

Massachusetts↗
USGS2002

Ground-Water Resource Assessment in the Rio Grande de Manati Alluvial Plain, Rio Arriba Saliente Area, Puerto Rico

The alluvial aquifer within a 160-acre area of the Rio Grande de Manati alluvial plain was investigated to evaluate its potential as a water-supply source for the Barrios Rio Arriba Saliente and Pugnado Afuera, municipio of Manati, Puerto Rico. Analysis of well boring samples and the results of electric resistivity surveys indicate that the average thickness of the unconsolidated alluvial deposits in the study area is about 100 to 110 feet. The alluvium is a mixture of sand and gravel, which generally has a porosity of 0.2 to 0.35. Short-duration pump tests in small-diameter piezometers indicate that the alluvial aquifer has a hydraulic conductivity of about 200 feet per day and a transmissivity of about 7,900 feet squared per day. Analyses of water levels in piezometers, combined with stage measurements at a series of surveyed reference points along the Rio Grande de Manati channel, indicate that the water-table gradient in the alluvial aquifer is about 0.001, and that ground-water flow is generally from south to north, in the general direction of river flow. The water-table data indicate that the Rio Grande de Manati is the principal source of ground-water recharge to the alluvial aquifer in the study area. Because base flow for the Rio Grande de Manati is usually greater than 44 cubic feet per second, a continuous withdrawal rate of 0.5 to 1.0 cubic foot per second (225 to 450 gallons per minute) from a production well is possible. Chemical analysis of a ground-water sample indicates that the alluvial aquifer water meets U.S. Environmental Protection Agency secondary standards for selected constituents. Bacteriological analysis of ground-water samples indicates that the ground water contains little or no fecal coliform or fecal streptococcus bacteria. Although long-term data from upstream of the study area indicate high levels of fecal coliform and fecal streptococcus prior to 1996, bacteriological analyses of Rio Grande de Manati water samples obtained during the present study indicate that fecal coliform and fecal streptococcus concentrations are within the standards for surface water intended for use (or with the potential for use) as a raw source of public water supply in Puerto Rico. If a production well were constructed in the study area, it would be located close to the river channel (within 500 to 800 feet). Pumping from the porous and permeable alluvial aquifer close to the river channel could substantially enhance recharge from the Rio Grande de Manati channel to the aquifer. Enhanced recharge could shorten travel times for ground water in the aquifer, which might not allow sufficient time to attenuate bacteria and viruses. Travel times for bacteria moving from the river channel to a hypothetical production well were estimated using the numerical transport model MODFLOW/MT3DMS with an uncalibrated model of the alluvial aquifer. The model assumes a well pumping at 1 cubic foot per second. The transport of particles from the river to the well is most sensitive to the porosity of the aquifer and the pumping rate of the well. Sensitivity analysis indicates that a decrease in pumpage will increase the time of travel for particles to move from the river to the pumping well. The model indicates that the leading edge of a plume would reach the production well in about 40 days assuming a porosity of 0.20, 60 days assuming a porosity of 0.275, and about 70 days assuming a porosity of 0.35. If the well were moved 50 feet further from the river, the leading edge of the plume would reach the well in about 50 days assuming a porosity of 0.20 and about 70 days assuming a porosity of 0.275. These estimates are considered worse case estimates because no decay rate was included in the simulation, and because the hypothetical well was located in the center of the alluvial plain rather than further eastward, away from the river channel.

Water-Resources Investigations Report↗
USGS2002

Evaluation of recharge to the Skunk Creek Aquifer from a constructed wetland near Lyons, South Dakota

A wetland was constructed in the Skunk Creek flood plain near Lyons in southeast South Dakota to mitigate for wetland areas that were filled during construction of a municipal golf course for the city of Sioux Falls. A water-rights permit was obtained to allow the city to pump water from Skunk Creek into the wetland during times when the wetland would be dry. The amount of water seeping through the wetland and recharging the underlying Skunk Creek aquifer was not known. The U.S. Geological Survey, in cooperation with the city of Sioux Falls, conducted a study during 1997-2000 to evaluate recharge to the Skunk Creek aquifer from the constructed wetland. Three methods were used to estimate recharge from the wetland to the aquifer: (1) analysis of the rate of water-level decline during periods of no inflow; (2) flow-net analysis; and (3) analysis of the hydrologic budget. The hydrologic budget also was used to evaluate the efficiency of recharge from the wetland to the aquifer. Recharge rates estimated by analysis of shut-off events ranged from 0.21 to 0.82 foot per day, but these estimates may be influenced by possible errors in volume calculations. Recharge rates determined by flow-net analysis were calculated using selected values of hydraulic conductivity and ranged from 566,000 gallons per day using a hydraulic conductivity of 0.5 foot per day to 1,684,000 gallons per day using a hydraulic conductivity of 1.0 foot per day. Recharge rates from the hydrologic budget varied from 0.74 to 0.85 foot per day, and averaged 0.79 foot per day. The amount of water lost to evapotranspiration at the study wetland is very small compared to the amount of water seeping from the wetland into the aquifer. Based on the hydrologic budget, the average recharge efficiency was estimated as 97.9 percent, which indicates that recharging the Skunk Creek aquifer by pumping water into the study wetland is highly efficient. Because the Skunk Creek aquifer is composed of sand and gravel, the 'recharge mound' is less distinct than might be found in an aquifer composed of finer materials. However, water levels recorded from piezometers in and around the wetland do show a higher water table than periods when the wetland was dry. The largest increases in water level occur between the wetland channel and Skunk Creek. The results of this study demonstrate that artificially recharged wetlands can be useful in recharging underlying aquifers and increasing water levels in these aquifers.

Water-Resources Investigations Report↗
USGS2002

Streamflow, water quality, and contaminant loads in the lower Charles River Watershed, Massachusetts, 1999-2000

Streamflow data and dry-weather and stormwater water-quality samples were collected from the main stem of the Charles River upstream of the lower Charles River (or the Basin) and from four partially culverted urban streams that drain tributary subbasins in the lower Charles River Watershed. Samples were collected between June 1999 and September 2000 and analyzed for a number of potential contaminants including nitrate (plus nitrite), ammonia, total Kjeldahl nitrogen, phosphorus, cadmium, chromium, copper, lead, and zinc; and water-quality properties including specific conductance, turbidity, biochemical oxygen demand, fecal coliform bacteria, Entero-coccus bacteria, total dissolved solids, and total suspended sediment. These data were used to identify the major pathways and to determine the magnitudes of contaminants loads that contribute to the poor water quality of the lower Charles River. Water-quality and streamflow data, for one small urban stream and two storm drains that drain subbasins with uniform (greater than 73 percent) land use (including single-family residential, multifamily residential, and commercial), also were collected. These data were used to elucidate relations among streamflow, water quality, and subbasin characteristics. Streamflow in the lower Charles River Watershed can be characterized as being unsettled and flashy. These characteristics result from the impervious character of the land and the complex infrastructure of pipes, pumps, diversionary canals, and detention ponds throughout the watershed. The water quality of the lower Charles River can be considered good?meeting water-quality standards and guidelines?during dry weather. After rainstorms, however, the water quality of the river becomes impaired, as in other urban areas. The poor quality of stormwater and its large quantity, delivered over short periods (hours and days), together with illicit sanitary cross connections, and combined sewer overflows, results in large contaminant loads that appear to exceed the river?s assimilative capacity. Annual contaminant loads from stormwater discharges directly to the lower Charles River are large, but most dry-weather and stormwater contaminant loads measured in this study originate from upstream of the Watertown Dam and are delivered to the lower Charles River in mainstem flows. An exception is fecal coliform bacteria. Stony Brook, a large tributary influenced by combined sewer overflow, contributed almost half of the annual fecal coliform load to the lower Charles River for Water Year 2000. Much of this fecal coliform bacteria load is discharged from Stony Brook to the lower Charles River during rain-storms. Estimated stormwater loads for future conditions suggest that sewer separation in the Stony Brook Subbasin might reduce loads of constituents associated with sewage but increase loads of constituents associated with street runoff. The unique environment offered by the lower Charles River must be considered when the environmental implications of large contaminant loads are interpreted. In particular, the lower Charles River has low hydraulic gradients, a lack of tidal flushing, a lack of natural uncontaminated sediment from erosion of upstream uncontaminated soils, and an anoxic, sulfide-rich bottom layer that forms a non-tidal salt wedge in the downstream part of the lower Charles River. Individually and in combination, these characteristics may increase the likelihood of adverse effects of some contaminants on the water, biota, and sediment of the lower Charles River.

Water-Resources Investigations Report↗
USGS2002

Nutrient dynamics in five off-stream reservoirs in the lower South Platte River basin, March-September 1995

In 1995, the U.S. Geological Survey conducted a study to characterize nutrient concentrations in five off-stream reservoirs in the lower South Platte River Basin?Riverside, Jackson, Prewitt, North Sterling, and Julesburg. These reservoirs are critical sources of irrigation water for agricultural areas, and several also are used for fishing, boating, swimming, hunting, and camping. Data collected for this study include depth profiles of water temperature, dissolved oxygen, pH, and specific conductance; nutrient species concentrations in the water column, bottom sediment, and inflow and outflow canals; and chlorophyll-a concentrations in the water column. Data were collected during the irrigation season from March through September 1995 at five sites each in Riverside, Jackson, Prewitt, and Julesburg Reservoirs and at six sites in North Sterling Reservoir. The five reservoirs studied are located in similar geographic, climatic, and land-use areas and, as a result, have a number of similarities in their internal nutrient dynamics. Nitrogen concentrations in the reservoirs were highest in March and decreased through September as a result of dilution from river inflows and biological activity. From March through June, decreases in nitrogen concentrations in the river and biological activity contributed to decreases in reservoir concentrations. From July through September, inflows from the river were cut off, and biological activity in the reservoirs led to further decreases in nitrate concentrations, which fell to near or below detectable levels. Phosphorus concentrations in the reservoirs did not show the same consistent decrease from March through September. Phosphorus likely was recycled continuously back to algae during the study period through processes such as excretion from fish, decay of aquatic plants and animals, and release of orthophosphate from bottom sediment during periods of low oxygen. With the exception of phosphorus in Jackson Reservoir, the reservoirs acted as a sink for both nitrogen and phosphorus; the percentage of the total mass (initial storage plus inflows) trapped in the reservoirs during the study period ranged from 49 to 88 percent for nitrogen and from 20 to 86 percent for phosphorus. The nutrient loading, morphology, and operation of the five reservoirs differed, however, leading to several important differences in nutrient dynamics among the reservoirs. Mean nutrient concentrations during the study period decreased in a downstream direction from Riverside Reservoir to Julesburg Reservoir because concentrations in the source water?the South Platte River?decreased downstream as a result of increased distance from wastewater loading upstream from Kersey, Colorado, and the replacement of diverted river water with more dilute ground-water return flow. North Sterling was an exception to this decrease; the strong stratification and resulting anoxia that developed in the reservoir led to nutrient release from the bottom sediments that offset the decrease in external nutrient loading. Variations in nutrient loading also contributed to differences in the nutrient limiting algal growth in the reservoirs, as indicated by mass nitrogen:phosphorus ratios. In Riverside and Jackson Reservoirs, nitrogen became the potential limiting nutrient by midsummer as biological activity depleted the available supply of nitrogen while the high initial phosphorus load was recycled. Prewitt, North Sterling, and Julesburg Reservoirs, with lower initial loadings of phosphorus, were phosphorus-limited throughout the study period, with additional colimitation of nitrogen as biological uptake reduced nitrogen concentrations to near or below laboratory detection limits. The percentage of the total nitrogen and phosphorus mass lost through outflow and trapped in the reservoir due to processes such as biological uptake and sedimentation varied between reservoirs.Generally, reservoirs with short residence times such as North Ste

Water-Resources Investigations Report↗
USGS2002

Ground-water flow and numerical simulation of recharge from streamflow infiltration near Pine Nut Creek, Douglas County, Nevada

Ground-water flow and recharge from infiltration near Pine Nut Creek, east of Gardnerville, Nevada, were simulated using a single-layer numerical finite-difference model as part of a study made by the U.S. Geological Survey in cooperation with the Carson Water Subconservancy District. The model was calibrated to 190 water-level measurements made in 27 wells in December 2000, and in 9 wells from August 1999 through April 2001. The purpose of this study was to estimate reasonable limits for the approximate volume of water that may be stored by recharge through infiltration basins, and the rate at which recharged water would dissipate or move towards the valley floor. Measured water levels in the study area show that infiltration from the Allerman Canal and reservoir has created a water-table mound beneath them that decreases the hydraulic gradient east of the canal and increases the gradient west of the canal. North of Pine Nut Creek, the mound causes ground water to flow toward the northern end of the reservoir. South of Pine Nut Creek, relatively high water levels probably are maintained by the mound beneath the Allerman Canal and possibly by greater rates of recharge from the southeast. Water-level declines near Pine Nut Creek from August 1999 through April 2001 probably are caused by dissipation of recharge from infiltration of Pine Nut Creek streamflow in the springs of 1998 and 1999. Using the calibrated model, a simulation of recharge through a hypothetical infiltration basin covering 12.4 acres near Pine Nut Creek applied 700 acre-feet per year of recharge over a six-month period, for a total of 3,500 acre-feet after 5 consecutive years. This recharge requires a diversion rate of about 2 cubic feet per second and an infiltration rate of 0.3 foot per day. The simulations showed that recharge of 3,500 acre-feet caused water levels near the basin to rise over 70 feet, approaching land surface, indicating 3,500 acre-feet is the maximum that may be stored in a 5-year period, given the basin location and surface area used in the simulations. Greater amounts probably could be stored if separate infiltration basins were installed at different locations along the Pine Nut Creek alluvial fan, applying the recharge over a larger area. The water-table mound resulting from recharge extended 7,000 feet north, west, and south of the infiltration basin. After recharge ceased, water levels near the center of the mound declined rapidly to within 20 feet of initial levels after 2 years, and within 10 feet of initial levels after 7 years. The recharge mound dissipates laterally across the modeled area at decreasing rates over time. A water-level rise of 1 foot moved westward towards the valley floor 660 feet from peak conditions after 1 year, and averaged 550 feet, 440 feet, and 330 feet per year for the periods 1-4, 4-7, and 7-10 years, respectively, after recharge ceased. Simulations of subsequent pumping from hypothetical wells near the infiltration basin were made by applying pumping near the basin beginning 1 year after recharge of 3,500 acre-feet ceased. Pumping was applied over a 6-month period for 4 years from one well at 400 acre-feet per year, withdrawing 1,600 acre-feet or 45 percent of that recharged, and from two wells totaling 800 acre-feet per year, withdrawing 3,200 acre-feet or 90 percent of that recharged. Pumping of 1,600 acre-feet caused water-levels near the infiltration basin to decline only slightly below initial levels. Pumping of 3,200 acre-feet caused water-levels near the infiltration basin to decline a maximum of 30 feet below initial levels, with smaller declines extending laterally in all directions for 4,000 feet from the pumping wells. Water-level declines are a result of pumping at a rate sufficient to withdraw the majority of the water recharged through the infiltration basin. Although the declines may affect water levels in nearby domestic wells, the simulations show that water levels recover quickly after

Water-Resources Investigations Report↗
USGS2002

Concentrations of dissolved oxygen in the lower Puyallup and White Rivers, Washington, August and September 2000 and 2001

The U.S. Geological Survey, Washington State Department of Ecology, and Puyallup Tribe of Indians conducted a study in August and September 2001 to assess factors affecting concentrations of dissolved oxygen in the lower Puyallup and White Rivers, Washington. The study was initiated because observed concentrations of dissolved oxygen in the lower Puyallup River fell to levels ranging from less than 1 milligram per liter (mg/L) to about 6 mg/L on several occasions in September 2000. The water quality standard for the concentration of dissolved oxygen in the Puyallup River is 8 mg/L.This study concluded that inundation of the sensors with sediment was the most likely cause of the low concentrations of dissolved oxygen observed in September 2000. The conclusion was based on (1) knowledge gained when a dissolved-oxygen sensor became covered with sediment in August 2001, (2) the fact that, with few exceptions, concentrations of dissolved oxygen in the lower Puyallup and White Rivers did not fall below 8 mg/L in August and September 2001, and (3) an analysis of other mechanisms affecting concentrations of dissolved oxygen.The analysis of other mechanisms indicated that they are unlikely to cause steep declines in concentrations of dissolved oxygen like those observed in September 2000. Five-day biochemical oxygen demand ranged from 0.22 to 1.78 mg/L (mean of 0.55 mg/L), and river water takes only about 24 hours to flow through the study reach. Photosynthesis and respiration cause concentrations of dissolved oxygen in the lower Puyallup River to fluctuate as much as about 1 mg/L over a 24-hour period in August and September. Release of water from Lake Tapps for the purpose of hydropower generation often lowered concentrations of dissolved oxygen downstream in the White River by about 1 mg/L. The effect was smaller farther downstream in the Puyallup River at river mile 5.8, but was still observable as a slight decrease in concentrations of dissolved oxygen caused by photosynthesis and respiration. The upper limit on oxygen demand caused by the scour of anoxic bed sediment and subsequent oxidation of reduced iron and manganese is less than 1 mg/L. The actual demand, if any, is probably negligible.In August and September 2001, concentrations of dissolved oxygen in the lower Puyallup River did not fall below the water-quality standard of 8 mg/L, except at high tide when the saline water from Commencement Bay reached the monitor at river mile 2.9. The minimum concentration of dissolved oxygen (7.6 mg/L) observed at river mile 2.9 coincided with the maximum value of specific conductance. Because the dissolved-oxygen standard for marine water is 6.0 mg/L, the standard was not violated at river mile 2.9. The concentration of dissolved oxygen at river mile 1.8 in the White River dropped below the water-quality standard on two occasions in August 2001. The minimum concentration of 7.8 mg/L occurred on August 23, and a concentration of 7.9 mg/L was recorded on August 13. Because there was some uncertainty in the monitoring record for those days, it cannot be stated with certainty that the actual concentration of dissolved oxygen in the river dropped below 8 mg/L. However, at other times when the quality of the monitoring record was good, concentrations as low as 8.2 mg/L were observed at river mile 1.8 in the White River.

Washington↗
USGS2002

Water-quality and aquatic-community characteristics of selected reaches of the St. Croix River, Minnesota and Wisconsin, 2000

Synoptic sampling was used to determine chemical and biological characteristics of the St. Croix River within a study reach that extended from near Danbury, Wisconsin to the confluence with the Mississippi River at Prescott, Wisconsin. The study was conducted August 7- September 25, 2000 during summer low flow. Dissolved-residue concentrations were found to increase gradually as the river flows downstream, with an abrupt increase downstream of the confluence with the Sunrise River that was primarily attributed to an increase in calcium and magnesium. Dissolved residue concentrations were further augmented by increased yields of chloride and sulfate in the part of the St. Croix Basin between Nevers Dam near St. Croix Falls, Wisconsin and Marine on St. Croix, Minnesota. Nearly all of the nitrogen in transport was in the form of nitrate and organic nitrogen. Organic nitrogen, mainly in particulate form, accounted for most of the gain in total nitrogen load within the study reach. Nitrogen loading to the mainstem indicated relatively uniform nitrogen inputs from the Clam River, Kettle River, and Snake River watersheds. The rate of nitrogen load accrual increased downstream of the confluence with the Sunrise River and in the subreach extending from Nevers Dam through St. Croix Falls to Franconia, Minnesota. Nitrogen load also increased, primarily because of nitrate input, in the part of Lake St. Croix downstream of the confluence with the Kinnickinnic River. Total phosphorus concentrations and loads reflected variations in the amount of particulate phosphorus in transport. Phosphorus loading increased in the part of the St. Croix River that includes Danbury and the confluences of the Yellow River and Clam River. Phosphorus loading also increased downstream of the confluence with the Sunrise River, but the greatest load increase occurred between Nevers Dam and Franconia. Phosphorus load decreased substantially as the river flowed through the pooled reach of Lake St. Croix downstream of Stillwater. Suspended-sediment concentrations were low, ranging from 4.0 to 36 milligrams per liter. The small amount of sediment in transport was reflected in turbidity measurements that ranged from 0.5 to 3.6 Nephelometry Turbidity Units, and transparency tube measurements that were greater than 60 centimeters at all sites. Biological measures of resource quality change in the St. Croix River along its course from Danbury to Prescott. Changes in the biological indicators of resource quality (fish and invertebrate community composition) are most notable just upstream and downstream of the dam at St. Croix Falls, Wisconsin. Aquatic communities in the upper St. Croix River, from near Danbury to near Rush City, Minnesota, indicate minimal physical and chemical disturbance as evidenced by relatively high taxa richness and greater proportions of taxa intolerant to physical and chemical disturbance. In contrast, aquatic communities downstream of the Sunrise River to Marine on St. Croix indicate both physical and chemical disturbance. Resource monitoring, consisting of short-term diagnostic studies, may be needed in parts of the St. Croix River mainstem and tributaries where results from this study indicate constituent loading is greatest and where the aquatic community composition indicates disturbance. Longer-term trend monitoring may be needed to detect physical, chemical and biological responses to natural processes and human activities in the St. Croix River Basin.

Minnesota, Wisconsin↗
USGS2004

Relations between total-sediment load and peak discharge for rainstorm runoff on five ephemeral streams in Wyoming

Total-sediment loads transported by ephemeral flows are a function of rainstorm energy and peak discharge. Rainstorm energy, estimated by rainfall intensity, is the primary mechanism for soil-particle detachment. Vegetation, soil cohesiveness, and land slope also are related to the amount of sediment detached, but these factors remain nearly constant, except for seasonal or human-induced changes in vegetation. Thus, the largest variability in total-sediment loads is the result of variability in rainstorm energy. The magnitude of the peak discharge in a stream from a runoff-producing rainstorm is a function of the intensity and volume of rainfall. The greater the rainfall intensity for the same volume of rainfall, the larger the peak discharge. Therefore, for each drainage area a relation exists between the total-sediment load for a rainstorm and the peak discharge for the rainstorm, because both are a function of rainstorm energy. Total-sediment loads for runoff-producing rainstorms were computed from sample data collected at five ephemeral streams in semiarid areas of Wyoming. Regression analyses were used to develop equations relating total-sediment load to the peak discharge. Coefficients of determination ranged from 89 to 97 percent. Average standard errors ranged from 35 to 94 percent. The slopes of the lines defined by the equations were not different at the 95-percent level of significance, but the intercepts were significantly different for the five streams.

Water-Resources Investigations Report↗
USGS2002

Characterization of selenium in the lower Gunnison River basin, Colorado, 1988-2000

Selenium concentrations in certain water bodies in the lower Gunnison River Basin, including the lower Gunnison River and lower Uncompahgre River, have exceeded the Colorado water-quality standard of 5 micrograms per liter for selenium. A task force was formed in 1998 that consists of various government agencies, private irrigation companies, and local residents to address the selenium concerns in the lower Gunnison River Basin. The task force, working with the National Irrigation Water Quality Program, needed more detailed information on selenium loading in the basin to develop viable alternatives for remediating selenium in the lower Gunnison River Basin. In 1999-2000, the U.S. Geological Survey collected selenium data for tributaries of the Gunnison River downstream from the North Fork of the Gunnison and in the North Fork Basin. The largest selenium load in a tributary stream was in the Uncompahgre River, which accounted for about 38 percent of the selenium load in the Gunnison River at Whitewater. The North Fork of the Gunnison River accounted for about 7 percent of the selenium load in the Gunnison River. Two tributaries east of Delta, Sunflower Drain and Bonafide Ditch, consist primarily of irrigation return flows and were other major selenium sources to the Gunnison River. Some tributaries in the lower North Fork Basin had selenium concentrations exceeding 5 micrograms per liter. Except for several streams draining the Uncompahgre Plateau, many tributaries to the Gunnison River downstream from the North Fork had selenium concentrations exceeding 5 micrograms per liter. Except during occasional rain and snowmelt events, selenium loading from nonirrigated desert areas was minimal. Detailed characterization studies were done in 1999-2000 on Cedar Creek and Loutzenhizer Arroyo, which contribute the largest tributary selenium loads to the Uncompahgre River. Selenium concentrations in Cedar Creek downstream from Miguel Road ranged from 12 to 28 micrograms per liter in November 1999. Montrose Arroyo was the largest selenium source to Cedar Creek. On an annual basis, about 20 percent of the selenium load in Cedar Creek originates in the basin upstream from Miguel Road. Selenium concentrations in Loutzenhizer Arroyo ranged from 157 to 347 micrograms per liter in February 2000. A significant increase in selenium concentrations occurred in the stream reach between the Selig Canal and Falcon Road (LZU7). Although selenium concentrations in the west tributary of Loutzenhizer Arroyo were lower than in the main stem, the west tributary contributed about 41 percent of the selenium load. Downstream from the confluence with the west tributary to the mouth, selenium concentrations in the arroyo gradually decreased, and the increase in selenium load in the lower reach was small.

Water-Resources Investigations Report↗
USGS2002

Water quality in the Little Sac River basin near Springfield, Missouri, 1999-2001

The Little Sac River, north of Springfield, Missouri, flows through mainly agricultural and forest land. However, the quality of the river water is a concern because the river flows into Stockton Lake, which is a supplemental drinking water source for Springfield. Large bacterial densities and nutrient concentrations are primary concerns to the water quality of the river. A 29-river mile reach of the Little Sac River is on the 1998 list of waters of Missouri designated under section 303(d) of the Federal Clean Water Act because of fecal coliform densities larger than the Missouri Department of Natural Resources standard (hereinafter referred to as Missouri standard) of 200 colonies per 100 milliliters for whole-body contact recreation. During an investigation of the water quality in the Little Sac River by the U.S. Geological Survey, in cooperation with the Watershed Committee of the Ozarks, fecal coliform bacteria densities exceeded the Missouri standard (the standard applies from April 1 through October 31) in one sample from a site near Walnut Grove. At other sites on the Little Sac River, the Missouri standard was exceeded in two samples and equalled in one sample upstream from the Northwest Wastewater Treatment Plant (NW WTP) and in one sample immediately downstream from the NW WTP. Effluent from the NW WTP flows into the Little Sac River. Annually from April 1 through October 31, the effluent is disinfected to meet the Missouri standard for whole-body contact recreation. Fecal coliform bacteria densities in samples collected during this period generally were less than 100 colonies per 100 milliliters. For the rest of the year when the effluent was not disinfected, the bacteria densities in samples ranged from 50 (sample collected on November 1, 2000) to 10,100 colonies per 100 milliliters (both counts were non-ideal). When the effluent was disinfected and the fecal coliform bacteria density was small, samples from sites upstream and downstream from the NW WTP had a bacteria density larger than the density in the effluent. Other sources of bacteria are likely to be present in the study area in addition to the NW WTP. These potential sources include effluent from domestic septic systems and animal wastes. Nutrient concentrations in the Little Sac River immediately downstream from the NW WTP were affected by effluent from the NW WTP and possibly other sources. At two sites upstream from the NW WTP, median nitrite plus nitrate concentrations were 1.1 and 1.4 milligrams per liter. The median nitrite plus nitrate concentration for the effluent from the NW WTP was 6.4 milligrams per liter, and the median concentration decreased downstream in the Little Sac River to 2.2, 1.2, and 0.56 milligrams per liter. The effects of the effluent from the NW WTP on the water quality of the Little Sac River downstream from the NW WTP were reflected in an increase in discharge (effluent from the NW WTP can be as much as 50 percent of the flow at the site about 1.5 river miles downstream from the NW WTP), an increase in specific conductance values, an increase in several inorganic constituent concentrations, including calcium, magnesium, and sulfate, and a large increase in sodium and chloride concentrations. The effluent from the NW WTP seemed to have no effect on the pH value, temperature, and dissolved oxygen concentrations in the Little Sac River. Results of repetitive element polymerase chain reaction (rep-PCR) pattern analysis indicated that most Escherichia coli ( E. coli ) bacteria in water samples probably were from nonhuman sources, such as horses and cattle. The rep-PCR pattern analysis indicated that horses were an important source of E. coli downstream from the NW WTP, which was consistent with horses pastured adjacent to the sampling site. Fecal coliform bacteria loads increased upstream from the NW WTP from the most upstream site to the site immediately upstream from the NW WTP. Loads in the effluent from the NW WTP and also those in the Little Sac River downstream from the NW WTP were dependent on the treatment of the effluent. When the effluent was not disinfected, the loads in the effluent increased from those upstream. Downstream in the Little Sac River, the loads decreased, but then increased at the most downstream site. The increase may be a result of increased loads from tributaries and other sources not sampled during the study. When the effluent was disinfected, fecal coliform bacteria loads were less than loads in samples from the Little Sac River downstream from the NW WTP.

Water-Resources Investigations Report↗
USGS2002

Simulation of ground-water flow and delineation of areas contributing recharge within the Mt. Simon-Hinckley aquifer to well fields in the Prairie Island Indian Community, Minnesota

The Prairie Island Indian Community in east-central Minnesota uses ground water from the Mt. Simon-Hinckley aquifer as its source of water supply. Tribal officials implemented a Source Water Protection Program to protect the quality of this water. Areas of contributing recharge were delineated for two community well fields. At well field A are two wells 325 m apart, and at well field B are two wells 25 m apart. A steady state single layer, two-dimensional ground-water flow model constructed with the computer program MODFLOW,combined with the particle-tracking computer program MODPATH, was used to track water particles (upgradient) from the two well fields. A withdrawal rate of 625 m 3 /d was simulated for each well field. The ground-water flow paths delineated areas of contributing recharge that are 0.38 and 0.65 km 2 based on 10- and 50-year travel times, respectively. The flow paths that define these areas extend for maximum distances of about 350 and 450 m, respectively, from the wells. At well field A the area of contributing recharge was delineated for each well as separate withdrawal points. At well field B the area of contributing recharge was delineated for the two wells as a single withdrawal point. Delineation of areas of contributing recharge to the well fields from land surface would require construction of a multi-layer ground-water flow model.

Minnesota, Wisconsin↗
USGS2002

Evaluation of factors affecting ice forces at selected bridges in South Dakota

During 1998-2002, the U.S. Geological Survey, in cooperation with the South Dakota Department of Transportation (SDDOT), conducted a study to evaluate factors affecting ice forces at selected bridges in South Dakota. The focus of this ice-force evaluation was on maximum ice thickness and ice-crushing strength, which are the most important variables in the SDDOT bridge-design equations for ice forces in South Dakota. Six sites, the James River at Huron, the James River near Scotland, the White River near Oacoma/Presho, the Grand River at Little Eagle, the Oahe Reservoir near Mobridge, and the Lake Francis Case at the Platte-Winner Bridge, were selected for collection of ice-thickness and ice-crushing-strength data. Ice thickness was measured at the six sites from February 1999 until April 2001. This period is representative of the climate extremes of record in South Dakota because it included both one of the warmest and one of the coldest winters on record. The 2000 and 2001 winters were the 8th warmest and 11th coldest winters, respectively, on record at Sioux Falls, South Dakota, which was used to represent the climate at all bridges in South Dakota. Ice thickness measured at the James River sites at Huron and Scotland during 1999-2001 ranged from 0.7 to 2.3 feet and 0 to 1.7 feet, respectively, and ice thickness measured at the White River near Oacoma/Presho site during 2000-01 ranged from 0.1 to 1.5 feet. At the Grand River at Little Eagle site, ice thickness was measured at 1.2 feet in 1999, ranged from 0.5 to 1.2 feet in 2000, and ranged from 0.2 to 1.4 feet in 2001. Ice thickness measured at the Oahe Reservoir near Mobridge site ranged from 1.7 to 1.8 feet in 1999, 0.9 to 1.2 feet in 2000, and 0 to 2.2 feet in 2001. At the Lake Francis Case at the Platte-Winner Bridge site, ice thickness ranged from 1.2 to 1.8 feet in 2001. Historical ice-thickness data measured by the U.S. Geological Survey (USGS) at eight selected streamflow-gaging stations in South Dakota were compiled for 1970-97. The gaging stations included the Grand River at Little Eagle, the White River near Oacoma, the James River near Scotland, the James River near Yankton, the Vermillion River near Wakonda, the Vermillion River near Vermillion, the Big Sioux River near Brookings, and the Big Sioux River near Dell Rapids. Three ice-thickness-estimation equations that potentially could be used for bridge design in South Dakota were selected and included the Accumulative Freezing Degree Day (AFDD), Incremental Accumulative Freezing Degree Day (IAFDD), and Simplified Energy Budget (SEB) equations. These three equations were evaluated by comparing study-collected and historical ice-thickness measurements to equation-estimated ice thicknesses. Input data required by the equations either were collected or compiled for the study or were obtained from the National Weather Service (NWS). An analysis of the data indicated that the AFDD equation best estimated ice thickness in South Dakota using available data sources with an average variation about the measured value of about 0.4 foot. Maximum potential ice thickness was estimated using the AFDD equation at 19 NWS stations located throughout South Dakota. The 1979 winter (the coldest winter on record at Sioux Falls) was the winter used to estimate the maximum potential ice thickness. The estimated maximum potential ice thicknesses generally are largest in northeastern South Dakota at about 3 feet and are smallest in southwestern and south-central South Dakota at about 2 feet. From 1999 to 2001, ice-crushing strength was measured at the same six sites where ice thickness was measured. Ice-crushing-strength measurements were done both in the middle of the winter and near spring breakup. The maximum ice-crushing strengths were measured in the mid- to late winter before the spring thaw. Measured ice-crushing strengths were much smaller near spring breakup. Ice-crushing strength measured at the six sites

Water-Resources Investigations Report↗
USGS2002

Evaluation of passive diffusion bag and dialysis samplers in selected wells at Hickam Air Force Base, Hawaii, July 2001

Field comparisons of chemical concentrations obtained from dialysis samplers, passive diffusion bag samplers, and low-flow samplers showed generally close agreement in most of the 13 wells tested during July 2001 at Hickam Air Force Base, Hawaii. The data for chloride, sulfate, iron, alkalinity, arsenic, and methane appear to show that the dialysis samplers are capable of accurately collecting a passive sample for these constituents. In general, the comparisons of volatile organic compound concentrations showed a relatively close correspondence between the two different types of diffusion samples and between the diffusion samples and the low-flow samples collected in most wells. Divergence appears to have resulted primarily from the pumping method, either producing a mixed sample or water not characteristic of aquifer water moving through the borehole under ambient conditions. The fact that alkalinity was not detected in the passive diffusion bag samplers, highly alkaline waters without volatilization loss from effervescence, which can occur when a sample is acidified for preservation. Both dialysis and passive diffusion bag samplers are relatively inexpensive and can be deployed rapidly and easily. Passive diffusion bag samplers are intended for sampling volatile organic compounds only, but dialysis samplers can be used to sample both volatile organic compounds and inorganic solutes. Regenerated cellulose dialysis samplers, however, are subject to biodegradation and probably should be deployed no sooner than 2 weeks prior to recovery. 1 U.S. Geological Survey, Columbia, South Carolina. 2 Air Florce Center for Environmental Excellence, San Antionio, Texas.

Hawaii↗