Geology ReportsSearch

SEARCH · Geology Reports

Results for “Cooperative Park Studies Unit 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.

87 records · Page 5Linked to original sources

Geologic map of the Rifle Falls quadrangle, Garfield County, Colorado

New 1:24,000-scale geologic map of the Rifle Falls 7.5' quadrangle, in support of the USGS Western Colorado I-70 Corridor Cooperative Geologic Mapping Project, provides new interpretations of the stratigraphy, structure, and geologic hazards in the area of the southwest flank of the White River uplift. Bedrock strata include the Upper Cretaceous Iles Formation through Ordovician and Cambrian units. The Iles Formation includes the Cozzette Sandstone and Corcoran Sandstone Members, which are undivided. The Mancos Shale is divided into three members, an upper member, the Niobrara Member, and a lower member. The Lower Cretaceous Dakota Sandstone, the Upper Jurassic Morrison Formation, and the Entrada Sandstone are present. Below the Upper Jurassic Entrada Sandstone, the easternmost limit of the Lower Jurassic and Upper Triassic Glen Canyon Sandstone is recognized. Both the Upper Triassic Chinle Formation and the Lower Triassic(?) and Permian State Bridge Formation are present. The Pennsylvanian and Permian Maroon Formation is divided into two members, the Schoolhouse Member and a lower member. All the exposures of the Middle Pennsylvanian Eagle Evaporite intruded into the Middle Pennsylvanian Eagle Valley Formation, which includes locally mappable limestone beds. The Middle and Lower Pennsylvanian Belden Formation and the Lower Mississippian Leadville Limestone are present. The Upper Devonian Chaffee Group is divided into the Dyer Dolomite, which is broken into the Coffee Pot Member and the Broken Rib Member, and the Parting Formation. Ordovician through Cambrian units are undivided. The southwest flank of the White River uplift is a late Laramide structure that is represented by the steeply southwest-dipping Grand Hogback, which is only present in the southwestern corner of the map area, and less steeply southwest-dipping older strata that flatten to nearly horizontal attitudes in the northern part of the map area. Between these two is a large-offset, mid-Tertiary(?) Rifle Falls normal fault, that dips southward placing Leadville Limestone adjacent to Eagle Valley and Maroon Formations. Diapiric Eagle Valley Evaporite intruded close to the fault on the down-thrown side and presumably was injected into older strata on the upthrown block creating a blister-like, steeply north-dipping sequence of Mississippian and older strata. Also, removal of evaporite by either flow or dissolution from under younger parts of the strata create structural benches, folds, and sink holes on either side of the normal fault. A prominent dipslope of the Morrison-Dakota-Mancos part of the section forms large slide blocks that form distinctly different styles of compressive deformation called the Elk Park fold and fault complex at different parts of the toe of the slide. The major geologic hazard in the area consist of large landslides both associated with dip-slope slide blocks and the steep slopes of the Eagle Valley Formation and Belden Formation in the northern part of the map. Significant uranium and vanadium deposits were mined prior to 1980.

Colorado

Ground-water resources of the Clifton Park area, Saratoga County, New York

Ground water is the sole source of public water supply for Clifton Park, a growing suburban community north of Albany, New York. Increasing water demand, coupled with concerns over ground-water quantity and quality, led the Clifton Park Water Authority in 1995 to initiate a cooperative study with the U.S. Geological Survey to update and refine the understanding of ground-water resources in the area. Ground-water resources are largely associated with three aquifers in the eastern half of the area. These aquifers overlie or encompass the Colonie Channel, a north-south-oriented bedrock channel that is filled primarily with lacustrine glacial deposits. The three aquifers are: (1) an unconfined lacustrine sand aquifer, (2) the Colonie Channel aquifer, which is confined within the deepest parts of the channel and variably confined and unconfined within the shallower, peripheral channel areas, and (3) an unconfined alluvial aquifer beneath the Mohawk River flood plain, which represents the southern limit of the study area. The lacustrine sand aquifer has little potential for large-scale withdrawals because it is predominantly fine grained and is susceptible to contamination from human activities at land surface. Water from this aquifer can, however, recharge the underlying peripheral parts of the Colonie Channel aquifer where hydraulic connections are present. The Colonie Channel aquifer consists of thin sand and gravel and (or) shallow, fractured bedrock over much of the channel area; discontinuous deposits of thicker (more than 20 feet) sand and gravel are common in the peripheral channel areas. The deepest, or central, channel area of this aquifer is isolated from the overlying lacustrine sand aquifer by a continuous lacustrine silt and clay unit, which is the primary channel-fill deposit. The most productive areas of the Colonie Channel aquifer are typically the shallow peripheral areas, where conditions range from unconfined to confined. The most productive aquifer within the area is the alluvial aquifer, which is sustained to an unknown extent by induced infiltration of Mohawk River water. The chemical composition of ground water within the Clifton Park area varies widely in response to hydrogeologic setting, pumpage, and contamination from human activities. These chemical differences can be used to deduce ground-water flow paths within and between the unconfined and confined areas of the aquifer system. Six water types are defined; three are naturally occurring and three are the result of human activities. Precipitation that infiltrates the land surface is the sole source of recharge to the lacustrine sand aquifer; precipitation also recharges the alluvial aquifer and unconfined parts of the Colonie Channel aquifer. Ground-water withdrawals from confined or unconfined peripheral areas of the Colonie Channel aquifer induce flow from recharge areas, from the underlying bedrock, or from other confined aquifer areas. The rate of recharge to the confined central area of the Colonie Channel aquifer appears to be low. Potentiometric levels as much as 100 feet below water-table levels in the overlying lacustrine sand aquifer indicate two large depressions in the potentiometric surface; these depressions indicate that withdrawals from this aquifer have cumulatively exceeded the recharge rates. Localized recharge of the central channel area apparently occurs from two peripheral channel areas that are characterized by zones of elevated water levels and (or) by water chemistry that differs from those within the central channel area. Recharge from, or hydraulic connection with, adjoining segments of the Colonie Channel aquifer to the north and south is likely, but the potential for significant recharge is low because the aquifer is thin and poorly permeable.

New York

Using continuous measurements of turbidity to predict suspended-sediment concentrations, loads, and sources in Flat Creek through the town of Jackson, Wyoming, 2019−20 — A pilot study

Flat Creek, a tributary to the Snake River in northwestern Wyoming, is an important source of irrigation water, fish and wildlife habitat, and local recreation. Since 1996, a section of Flat Creek within the town of Jackson has failed to meet Wyoming Department of Environmental Quality’s surface-water-quality standards for total suspended solids and turbidity required by its State water-use classification. Wyoming Department of Environmental Quality water-quality standards prohibit increases of greater than 10 nephelometric turbidity units (NTU) because of human activities in streambodies of Wyoming. Sediment loading from urban stormwater runoff is hypothesized in previous publications to be the primary cause of impairment, but the relative fine sediment contributions from various sources have not been quantified. In cooperation with the Teton Conservation District, the U.S. Geological Survey began a pilot study in the Flat Creek drainage basin to investigate the use of continuous turbidity measurements to predict suspended-sediment concentrations, loads, and sources through the town of Jackson, Wyoming. The predictions were based on turbidity measurements collected every 15 minutes during parts of water years 2019 and 2020. Analysis of differences in the more than 15,000 turbidity measurements coincident between upstream and downstream streamgages indicated that differences of 10 formazin nephelometric units (FNU) or greater composed about 1 percent of the total accepted measurements during the 2019 and 2020 measurement periods. The median difference in measured turbidity between coincident records at the upstream and downstream streamgages in 2019 was 0.20 FNU and the median difference in 2020 was 0.0 FNU. Calculations of mean total sediment loads in Flat Creek during 2019 and 2020 indicate substantially more suspended-sediment was in Flat Creek below the town of Jackson than above town. Mean total calculated suspended-sediment loads at the upstream streamgage were 26 percent in 2019 and 21 percent in 2020 of the mean total suspended-sediment loads at the downstream streamgage. For measurements occurring at the same time (coincident), mean calculated suspended-sediment loads entering the town of Jackson from Flat Creek were 39 percent in 2019 and 35 percent in 2020 of those loads exiting town in Flat Creek. Incorporating statistical model uncertainty, mean differences between predicted suspended-sediment loads could potentially be zero. The annual period of operations of the South Park Supply Ditch, which diverts water into Flat Creek from the Gros Ventre River, constituted between 91 and 90 percent of the total calculated suspended-sediment load at the upstream streamgage, and between 88 and 87 percent of the loads at the downstream streamgage for coincident periods of record in 2019 and 2020, respectively. However, in the absence of simultaneous continuous monitoring and resulting measurements at the outlet of the South Park Supply Ditch, no robust method was available to quantify suspended-sediment loads from the ditch. A moving average filter was used to identify and isolate short-duration (minutes to hours) spikes in turbidity at the downstream streamgage that were likely caused by overland flow and urban runoff. Suspended-sediment loads during urban runoff constituted about 8 and 10 percent of the total calculated suspended-sediment loads at the downstream streamgage (Flat Creek below Cache Creek, near Jackson, Wyoming; U.S. Geological Survey streamgage 13018350), and 6 and 4 percent of the loads calculated for the record coincident with the upstream streamgage in 2019 and 2020, respectively. Estimated suspended-sediment loads at the upstream streamgage during urban runoff events for the coincident period of record constitute 32 and 40 percent of the total estimated suspended-sediment loads at the downstream streamgage in 2019 and 2020, respectively, indicating sediment loads from urban runoff may contribute less than 10 percent, even as little as 5 percent, of the total sediment load exiting the town of Jackson on Flat Creek. Estimation of the proportion of suspended-sediment loads at the upstream site that originate from the South Park Supply Ditch or Cache Creek can only be done with assumptions but have the potential to be equivalent to or greater than calculated suspended-sediment loads associated with urban runoff.

Wyoming

Geohydrology and water quality of the stratified-drift aquifers in Upper Buttermilk Creek and Danby Creek Valleys, Town of Danby, Tompkins County, New York

In 2006, the U.S. Geological Survey, in cooperation with the Town of Danby and the Tompkins County Planning Department, began a study of the stratified-drift aquifers in the upper Buttermilk Creek and Danby Creek valleys in the Town of Danby, Tompkins County, New York. In the northern part of the north-draining upper Buttermilk Creek valley, there is only one sand and gravel aquifer, a confined basal unit that overlies bedrock. In the southern part of upper Buttermilk Creek valley, there are as many as four sand and gravel aquifers, two are unconfined and two are confined. In the south-draining Danby Creek valley, there is an unconfined aquifer consisting of outwash and kame sand and gravel (deposited by glacial meltwaters during the late Pleistocene Epoch) and alluvial silt, sand, and gravel (deposited by streams during the Holocene Epoch). In addition, throughout the study area, there are several small local unconfined aquifers where large tributaries deposited alluvial fans in the valley. The principal sources of recharge to the unconfined aquifers in the study area include direct infiltration of precipitation (rain and snowmelt) at land surface, unchanneled surface runoff from adjacent hillsides that seeps into the aquifer along the edges of the valley, groundwater inflow from adjacent till and bedrock that enters the aquifer along the sides of the valley, and seepage loss from upland-tributary streams where they flow over their alluvial fans in the valley. The percentages of all sources of recharge to the contiguous unconfined aquifer in Danby Creek valley include 16 percent from precipitation that falls directly over the aquifer, 55 percent from unchanneled surface runoff and groundwater inflow from hillsides, and 29 percent from losing tributary streams that cross the aquifer. The total annual recharge to the contiguous unconfined aquifer is 2.56 cubic feet per second (604 million gallons per year). The principal sources of recharge to the confined aquifers include precipitation that falls directly on the surficial confining unit, which then slowly flows vertically downward through the fine-grained sediments and enters the confined aquifer, and groundwater inflow from till and bedrock that borders the aquifer along adjacent hillsides and at the bottom of the valley. In addition, there is substantial amounts of recharge to the confined aquifers where the confining units are locally absent (forming windows) and where parts of the confining units consist of sediments of low to moderate permeability (forming a semiconfining layer). In the northern part of the study area (upper Buttermilk Creek valley), groundwater in the stratified-drift aquifers discharges to (1) domestic and commercial wells; (2) Buttermilk Creek in the area near the northern town border, and (3) and a small unnamed stream in a ravine in Buttermilk State Park just north of the town border. In the southern part of the study area (Danby Creek valley), groundwater discharges (1) to domestic, commercial, and farm wells; (2) to Danby Creek; (3) to a large wetland in the central parts of Danby Creek valley; and (4) as losses because of plant uptake and evaporation. About 300 people depend on groundwater from the upper Buttermilk Creek and Danby Creek stratified-drift aquifer system. An unconfined surficial aquifer about 8,000 feet (ft) long and as much as 800 ft wide, with a saturated thickness of about 20 ft, occupies the lower (southeastern most) 8,000 ft of Danby Creek valley within the Town of Danby. However, because the aquifer is thin, the volume of water stored in the aquifer is small and the potential for induced recharge from Danby Creek during summer periods of low flow is also small, an array of wells would probably be needed to provide sustainable continuous amount of water to large water users such as municipalities and industries. Additional data and a groundwater flow model would be required to estimate sustainable withdrawal from the confined aquifers in upper Buttermilk Creek valley. Well data from water-well drillers through 2012 indicate that the confined aquifers in upper Buttermilk Creek valley are thin (typically about 10 feet thick) and the reported well-yield data suggest these aquifers may not be capable of supplying sufficient water to meet the needs of municipalities and industries. However, additional geohydrologic data leading to calibration of a groundwater flow model would be needed to properly evaluate the long-term (multiple years) potential yield of the confined aquifer system in upper Buttermilk Creek valley and of the unconfined aquifer in Danby Creek valley. During 2007–10, groundwater samples were collected from 13 wells including 7 wells that are completed in the confined sand and gravel aquifers, 1 well that is completed in the unconfined aquifer, and 5 wells that are completed in the bedrock aquifers. Calcium dominates the cation composition and bicarbonate dominates the anion composition in most groundwater. Water quality in the study area generally meets state and Federal drinking-water standards but concentrations of some constituents exceeded the standards. The standards that were exceeded include sodium (3 samples), dissolved solids (1 sample), iron (3 samples), manganese (8 samples), and arsenic (1 sample).

New York

Effects of urbanization, construction activity, management practices, and impoundments on suspended-sediment transport in Johnson County, northeast Kansas, February 2006 through November 2008

The U.S. Geological Survey, in cooperation with the Johnson County, Kansas, Stormwater Management Program, investigated the effects of urbanization, construction activity, management practices, and impoundments on suspended-sediment transport in Johnson County from February 2006 through November 2008. Streamgages and continuous turbidity sensors were operated at 15 sites within the urbanizing 57-square-mile Mill Creek Basin, and 4 sites downstream from the other largest basins (49 to 66 square miles) in Johnson County. The largest sediment yields in Johnson County were observed downstream from basins with increased construction activity. Sediment yields attributed to the largest (68 acre) active construction site in the study area were 9,300 tons per square mile in 2007 and 12,200 tons per square mile in 2008; 5 to 55 times larger than yields observed at other sampling sites. However, given erodible soils and steep slopes at this site, sediment yields were relatively small compared to the range in historic values from construction sites without erosion and sediment controls in the United States (2,300 to 140,000 tons per square mile). Downstream from this construction site, a sediment forebay and wetland were constructed in series upstream from Shawnee Mission Lake, a 120-acre reservoir within Shawnee Mission Park. Although the original intent of the sediment forebay and constructed wetland were unrelated to upstream construction, they were nonetheless evaluated in 2008 to characterize sediment removal before stream entry into the lake. The sediment forebay was estimated to reduce 33 percent of sediment transported to the lake, whereas the wetland did not appear to decrease downstream sediment transport. Comparisons of time-series data and relations between turbidity and sediment concentration indicate that larger silt-sized particles were deposited within the sediment forebay, whereas smaller silt and clay-sized sediments were transported through the wetland and into the lake. Data collected at sites up and downstream from the constructed wetland indicated that hydraulic retention alone did not substantially reduce sediment loading to Shawnee Mission Lake. Mean-daily turbidity values at sampling sites downstream from basins with increased construction activity were compared to U.S. Environmental Protection Agency turbidity criteria designed to reduce discharge of pollutants from construction sites. The U.S. Environmental Protection Agency numeric turbidity criteria specifies that effluent from construction sites greater than 20 acres not exceed a mean-daily turbidity value of 280 nephelometric turbidity units beginning in 2011; this criteria will apply to sites greater than 10 acres beginning in 2014. Although numeric criteria would not have been applicable to data from sampling sites in Johnson County because they were not directly downstream from construction sites and because individual states still have to determine additional details as to how this criteria will be enforced, comparisons were made to characterize the potential of construction site effluent in Johnson County to exceed U.S. Environmental Protection Agency Criteria, even under extensive erosion and sediment controls. Numeric criteria were exceeded at sampling sites downstream from basins with increased construction activity for multiple days during the study period, potentially indicating the need for additional erosion and sediment controls and (or) treatment to bring discharges from construction sites into compliance with future numeric turbidity criteria. Among sampling sites in the Mill Creek Basin, sediment yields from the urbanizing Clear Creek Basin were approximately 2 to 3 times those from older, more stable urban or rural basins. Sediments eroded from construction sites adjacent to or surrounding streams appear to be more readily transported downstream, whereas sediments eroded from construction sites in headwater areas are more likely to

Scientific Investigations Report

Influence of recharge basins on the hydrology of Nassau and Suffolk Counties, Long Island, New York

An investigation of recharge basins on Long Island was made by the U.S. Geological Survey in cooperation with the New York State Department of Environmental Conservation, Nassau County Department of Public Works, Suffolk County Department of Environmental Control, and Suffolk County Water Authority. The major objectives of the study were to (1) catalog basic physical data on the recharge basins in use on Long Island, (2) measure quality and quantity of precipitation and inflow, (3) measure infiltration rates at selected recharge basins, and (4) evaluate regional effects of recharge basins on the hydrologic system of Long Island. The area of study consists of Nassau and Suffolk Counties -- about 1,370 square miles -- in eastern Long Island, N.Y. Recharge basins, numbering more than 2,100 on Long Island in 1969, are open pits in moderately to highly permeable sand and gravel deposits. These pits are used to dispose of storm runoff from residential, industrial, and commercial areas, and from highways, by infiltration of the water through the bottom and sides of the basins. The hydrology of three recharge basins on Long Island -- Westbury, Syosset, and Deer Park basins -- was studied. The precipitation-inflow relation showed that the average percentages of precipitation flowing into each basin were roughly equivalent to the average percentages of impervious areas in the total drainage areas of the basins. Average percentages of precipitation flowing into the basins as direct runoff were 12 percent at the Westbury basin, 10 percent at the Syosset basin, and 7 percent at the Deer Park basin. Numerous open-bottomed storm-water catch basins at Syosset and Deer Park reduced the proportion of inflow to those basins, as compared with the Westbury basin, which has only a few open-bottomed catch basins. Inflow hydrographs for each basin typify the usual urban runoff hydrograph -- steeply rising and falling limbs, sharp peaks, and short time bases. Unit hydrographs for the Westbury and the Syosset basins are not expected to change; however, the unit hydrograph for the Deer Park basin is expected to broaden somewhat as a result of additional future house construction within the drainage area. Infiltration rates averaged 0.9 fph (feet per hour) for 63 storms between July 1967 and May 1970 at the Westbury recharge basin, 0.8 fph for 22 storms from July 1969 to September 1970 at the Syosset recharge basin, and 0.2 fph for 24 storms from March to September 1970 at the Deer Park recharge basin. Low infiltration rates at Deer Park resulted mainly from (1) a high percentage of eroded silt, clay, and organic debris washed in from construction sites in the drainage area, which partly filled the interstices of the natural deposits, and (2) a lack of a well-developed plant-root system on the floor of the younger basin, which would have kept the soil zone more permeable. The apparent rate of movement of storm water through the unsaturated zone below each basin averaged 5.5 fph at Westbury, 3.7 fph at Syosset, and 3.1 fph at Deer Park. The rates of movement for storms during the warm months (April through October) were slightly higher than average, probably because the recharging water was warmer than it was during the rest of the year, and therefore, was slightly less viscous. On the average, a 1-inch rainfall resulted in a peak rise of the water table directly below each basin of 0.5 foot; a 2-inch rainfall resulted in a peak rise of about 2 feet. The mound commonly dissipated within 1 to 4 days at Westbury, 7 days to more than 15 days at Syosset, and 1 to 3 days at Deer Park, depending on the magnitude of the peak buildup. Average annual ground-water recharge was estimated to be 6.4 acre-feet at the Westbury recharge basin, 10.3 acre-feet at the Syosset recharge basin, and 29.6 acre-feet at the Deer Park recharge basin. Chemical composition of precipitation at Westbury, Syosset, and Deer Park drainage areas was similar:

Water Supply Paper

Summary of Environmental Monitoring and Assessment Program (EMAP) activities in South Dakota, 2000–2004

The U.S. Environmental Protection Agency (USEPA) initiated data-collection activities for the Environmental Monitoring and Assessment Program-West (EMAP-West) in South Dakota during 2000. The objectives of the study were to develop the monitoring tools necessary to produce unbiased estimates of the ecological condition of surface waters across a large geographic area of the western United States, and to demonstrate the effectiveness of those tools in a large-scale assessment. In 2001, the U.S. Geological Survey (USGS) and the South Dakota Department of Game, Fish and Parks (GF&P) established a cooperative agreement and assumed responsibility for completing the remaining assessments for the perennial, wadable streams of the EMAP-West in the State. Stream assessment sites were divided into two broad categories-the first category of sites was randomly selected and assigned by the USEPA for South Dakota. The second category consisted of sites that were specifically selected because they appeared to have reasonable potential for representing the best available physical, chemical, and biological conditions in the State. These sites comprise the second category of assessment sites and were called 'reference' sites and were selected following a detailed evaluation process. Candidate reference site data will serve as a standard or benchmark for assessing the overall ecological condition of the randomly selected sites. During 2000, the USEPA completed 22 statewide stream assessments in South Dakota. During 2001-2003, the USGS and GF&P completed another 42 stream assessments bringing the total of randomly selected stream assessments within South Dakota to 64. In addition, 18 repeat assessments designed to meet established quality-assurance/quality-control requirements were completed at 12 of these 64 sites. During 2002-2004, the USGS in cooperation with GF&P completed stream assessments at 45 candidate reference sites. Thus, 109 sites had stream assessments completed in South Dakota for EMAP-West (2000-2004). Relatively early in the EMAP-West stream-assessment process, it became apparent that for some streams in south-central South Dakota, in-stream conditions varied considerably over relatively short distances of only a few miles. These changes appeared to be a result of geomorphic changes associated with changes in the underlying geology. For these streams, moving stream assessment sites short distances upstream or downstream had the potential to provide substantially different bioassessment data. In order to obtain a better understanding of how geology influences stream conditions, two streams located in south-central South Dakota were chosen for multiple stream sampling at sites located along their longitudinal profile at points where notable changes in geomorphology were observed. Subsequently, three sites on Bear-in-the-Lodge Creek and three sites on Black Pipe Creek were selected for multiple stream sampling using EMAP-West protocols so that more could be learned about geologic influences on stream conditions. Values for dissolved oxygen and specific conductance generally increased from upstream to downstream locations on Bear-in-the-Lodge Creek. Values for pH and water temperature generally decreased from upstream to downstream locations. Decreasing water temperature could be indicative of ground-water inflows. Values for dissolved oxygen, pH, and water temperature generally increased from upstream to downstream locations on Black Pipe Creek. The increase in temperature at the lower sites is a result of less dense riparian cover, and the warmer water also could account for the lower concentrations of dissolved oxygen found in the lower reaches of Black Pipe Creek. Values for specific conductance were more than three times greater at the lower site (1,342 microsiemens per centimeter (?S/cm)) than at the upper site (434 ?S/cm). The increase probably occurs when the stream transitions from contacting the underlying Ar

South Dakota

Quality of water and sediment in streams affected by historical mining, and quality of Mine Tailings, in the Rio Grande/Rio Bravo Basin, Big Bend Area of the United States and Mexico, August 2002

The U.S. Geological Survey, in cooperation with the International Boundary and Water Commission - U.S. and Mexican Sections, the National Park Service, the Texas Commission on Environmental Quality, the Secretaria de Medio Ambiente y Recursos Naturales in Mexico, the Area de Proteccion de Flora y Fauna Canon de Santa Elena in Mexico, and the Area de Proteccion de Flora y Fauna Maderas del Carmen in Mexico, collected samples of stream water, streambed sediment, and mine tailings during August 2002 for a study to determine whether trace elements from abandoned mines in the area in and around Big Bend National Park have affected the water and sediment quality in the Rio Grande/Rio Bravo Basin of the United States and Mexico. Samples were collected from eight sites on the main stem of the Rio Grande/Rio Bravo, four Rio Grande/Rio Bravo tributary sites downstream from abandoned mines or mine-tailing sites, and 11 mine-tailing sites. Mines in the area were operated to produce fluorite, germanium, iron, lead, mercury, silver, and zinc during the late 1800s through at least the late 1970s. Moderate (relatively neutral) pHs in stream-water samples collected at the 12 Rio Grande/Rio Bravo main-stem and tributary sites indicate that water is well mixed, diluted, and buffered with respect to the solubility of trace elements. The highest sulfate concentrations were in water samples from tributaries draining the Terlingua mining district. Only the sample from the Rough Run Draw site exceeded the Texas Surface Water Quality Standards general-use protection criterion for sulfate. All chloride and dissolved solids concentrations in water samples were less than the general-use protection criteria. Aluminum, copper, mercury, nickel, selenium, and zinc were detected in all water samples for which each element was analyzed. Cadmium, chromium, and lead were detected in samples less frequently, and silver was not detected in any of the samples. None of the sample concentrations of aluminum, cadmium, chromium, nickel, selenium, and zinc exceeded the Texas Surface Water Quality Standards criteria for aquatic life-use protection or human health. The only trace elements detected in the water samples at concentrations exceeding the Texas Surface Water Quality Standards criterion for human health (fish consumption use) was lead at one site and mercury at 10 of 12 sites. Relatively high mercury concentrations distributed throughout the area might indicate sources of mercury in addition to abandoned mining areas. Streambed-sediment samples were collected from 12 sites and analyzed for 44 major and trace elements. In general, the trace elements detected in streambed-sediment samples were low in concentration, interpreted as consistent with background concentrations. Concentrations at two sites, however, were elevated compared to Texas Commission on Environmental Quality criteria. Concentrations of antimony, arsenic, cadmium, lead, silver, and zinc in the sample from San Carlos Creek downstream from La Esperanza (San Carlos) Mine exceeded the Texas Commission on Environmental Quality screening levels for sediment. The sample from Rough Run Draw, downstream from the Study Butte Mine, also showed elevated concentrations of arsenic, cadmium, and lead, but these concentrations were much lower than those in the San Carlos Creek sample and did not exceed screening levels. Elevated concentrations of multiple trace elements in streambed-sediment samples from San Carlos Creek and Rough Run Draw indicate that San Carlos Creek, and probably Rough Run Draw, have been adversely affected by mining activities. Fourteen mine-tailing samples from 11 mines were analyzed for 25 major and trace elements. All trace elements except selenium and thallium were detected in one or more samples. The highest lead concentrations were detected in tailings samples from the Boquillas, Puerto Rico, La Esperanza (San Carlos), and Tres Marias Mines, as might be expected because the tailings ar

Scientific Investigations Report

Geohydrology and Water Quality of the Valley-Fill Aquifer System in the Upper Sixmile Creek and West Branch Owego Creek Valleys in the Town of Caroline, Tompkins County, New York

In 2002, the U.S. Geological Survey, in cooperation with the Town of Caroline and Tompkins County Planning Department, began a study of the valley-fill aquifer system in upper Sixmile Creek and headwaters of West Branch Owego Creek valleys in the Town of Caroline, NY. The purpose of the study is to provide geohydrologic data to county and town planners as they develop a strategy to manage and protect their water resources. The first aquifer reach investigated in this series is in the Town of Caroline and includes the upper Sixmile Creek valley and part of West Branch Owego Creek valley. The portions of the valley-fill aquifer system that are comprised of saturated coarse-grained sediments including medium to coarse sand and sandy gravel form the major aquifers. Confined sand and gravel units form the major aquifers in the western and central portions of the upper Sixmile Creek valley, and an unconfined sand and gravel unit forms the major aquifer in the eastern portion of the upper Sixmile Creek valley and in the headwaters of the West Branch Owego Creek valley. The valley-fill deposits are thinnest near the edges of the valley where they pinch out along the till-mantled bedrock valley walls. The thickness of the valley fill in the deepest part of the valley, at the western end of the study area, is about 100 feet (ft); the thickness is greater than 165 ft on top of the Valley Heads Moraine in the central part of the valley. An estimated 750 people live over and rely on groundwater from the valley-fill aquifers in upper Sixmile Creek and West Branch Owego Creek valleys. Most groundwater withdrawn from the valley-fill aquifers is pumped from wells with open-ended 6-inch diameter casings; the remaining withdrawals are from shallow dug wells or cisterns that collect groundwater that discharges to springs (especially in the Brooktondale area). The valley-fill aquifers are the sources of water for about 200 households, several apartment complexes, two mobile home parks, a school, and several farms and small businesses. Most groundwater that is withdrawn from pumped wells is returned to the groundwater system via septic systems. Groundwater in the upper and basal confined aquifers in the upper Sixmile Creek valley is under artesian conditions everywhere except where the water discharges to springs along bluffs in the western end of the Sixmile Creek valley. Principal sources of recharge to the confined aquifers are (1) the sides of the valley where the confined aquifers may extend up along the flank of the bedrock valley wall and crop out at land surface or are overlain and in contact with surficial coarse-grained deltaic and fluvial sediments that provide a pathway through which direct precipitation and seepage losses from tributary streams can reach the buried aquifers, or (2) where the buried aquifers are isolated and receive recharge only from adjacent fine-grained sediment and bedrock. The base-flow and runoff components of total streamflow at two streamgages, Sixmile Creek at Brooktondale and Sixmile Creek at Bethel Grove, were calculated using hydrograph-separation techniques from 2003 to 2007 discharge records. Base flow constituted 64 and 56 percent of the total annual flow at the Brooktondale and Bethel Grove streamgages, respectively. Water-quality samples were collected from 2003 to 2005, with 10 surface-water samples collected seasonally during base-flow conditions at the Sixmile Creek at Brooktondale streamgage, and 12 samples were collected during base-flow conditions at several selected tributaries from 2004 to 2005. The predominant cation detected in the surface-water samples was calcium, but moderate amounts of magnesium, silica, and sodium were also detected; the major anions were bicarbonate, chloride, and sulfate. Sodium and chloride concentrations were relatively low in all samples but increased downstream from the Sixmile Creek sampling site at Six Hundred Road near Slaterville Springs, NY, to B

Scientific Investigations Report

Sequence stratigraphy, seismic stratigraphy, and seismic structures of the lower intermediate confining unit and most of the Floridan aquifer system, Broward County, Florida

Deep well injection and disposal of treated wastewater into the highly transmissive saline Boulder Zone in the lower part of the Floridan aquifer system began in 1971. The zone of injection is a highly transmissive hydrogeologic unit, the Boulder Zone, in the lower part of the Floridan aquifer system. Since the 1990s, however, treated wastewater injection into the Boulder Zone in southeastern Florida has been detected at three treated wastewater injection utilities in the brackish upper part of the Floridan aquifer system designated for potential use as drinking water. At a time when usage of the Boulder Zone for treated wastewater disposal is increasing and the utilization of the upper part of the Floridan aquifer system for drinking water is intensifying, there is an urgency to understand the nature of cross-formational fluid flow and identify possible fluid pathways from the lower to upper zones of the Floridan aquifer system. To better understand the hydrogeologic controls on groundwater movement through the Floridan aquifer system in southeastern Florida, the U.S. Geological Survey and the Broward County Environmental Planning and Community Resilience Division conducted a 3.5-year cooperative study from July 2012 to December 2015. The study characterizes the sequence stratigraphy, seismic stratigraphy, and seismic structures of the lower part of the intermediate confining unit aquifer and most of the Floridan aquifer system. Data obtained to meet the study objective include 80 miles of high-resolution, two-dimensional (2D), seismic-reflection profiles acquired from canals in eastern Broward County. These profiles have been used to characterize the sequence stratigraphy, seismic stratigraphy, and seismic structures in a 425-square-mile study area. Horizon mapping of the seismic-reflection profiles and additional data collection from well logs and cores or cuttings from 44 wells were focused on construction of three-dimensional (3D) visualizations of eight sequence stratigraphic cycles that compose the Eocene to Miocene Oldsmar, Avon Park, and Arcadia Formations. The mapping of these seismic-reflection and well data has produced a refined Cenozoic sequence stratigraphic, seismic stratigraphic, and hydrogeologic framework of southeastern Florida. The upward transition from the Oldsmar Formation to the Avon Park Formation and the Arcadia Formation embodies the evolution from (1) a tropical to subtropical, shallow-marine, carbonate platform, represented by the Oldsmar and Avon Park Formations, to (2) a broad, temperate, mixed carbonate-siliciclastic shallow marine shelf, represented by the lower part of the Arcadia Formation, and to (3) a temperate, distally steepened carbonate ramp represented by the upper part of the Arcadia Formation. In the study area, the depositional sequences and seismic sequences have a direct correlation with hydrogeologic units. The approximate upper boundary of four principal permeable units of the Floridan aquifer system (Upper Floridan aquifer, Avon Park permeable zone, uppermost major permeable zone of the Lower Floridan aquifer, and Boulder Zone) have sequence stratigraphic and seismic-reflection signatures that were identified on cross sections, mapped, or both, and therefore the sequence stratigraphy and seismic stratigraphy were used to guide the development of a refined spatial representation of these hydrogeologic units. In all cases, the permeability of the four permeable units is related to stratiform megaporosity generated by ancient dissolution of carbonate rock associated with subaerial exposure and unconformities at the upper surfaces of carbonate depositional cycles of several hierarchical scales ranging from high-frequency cycles to depositional sequences. Additionally, interparticle porosity also contributes substantially to the stratiform permeability in much of the Upper Floridan aquifer. Information from seismic stratigraphy allowed 3D geomodeling of hydrogeologic units—an approach never before applied to this area. Notably, the 3D geomodeling provided 3D visualizations and geocellular models of the depositional sequences, hydrostratigraphy, and structural features. The geocellular data could be used to update the hydrogeologic structure inherent to groundwater flow simulations that are designed to address the sustainability of the water resources of the Floridan aquifer system. Two kinds of pathways that could enable upward cross-formational flow of injected treated wastewater from the Boulder Zone have been identified in the 80 miles of high-resolution seismic data collected for this study: a near-vertical reverse fault and karst collapse structures. The single reverse fault, inferred to be of tectonic origin, is in extreme northeastern Broward County and has an offset of about 19 feet at the level of the Arcadia Formation. Most of the 17 karst collapse structures identified manifest as columniform, vertically stacked sagging seismic reflections that span early Eocene to Miocene age rocks equivalent to much of the Floridan aquifer system and the lower part of the overlying intermediate confining unit. In some cases, the seismic-sag structures extend upward into strata of Pliocene age. The seismic-sag structures are interpreted to have a semicircular shape in plan view on the basis of comparison to (1) other seismic-sag structures in southeastern Florida mapped with two 2D seismic cross lines or 3D data, (2) comparison to these structures located in other carbonate provinces, and (3) plausible extensional ring faults detected with multi-attribute analysis. The seismic-sag structures in the study area have heights as great as 2,500 vertical feet, though importantly, one spans about 7,800 feet. Both multi-attribute analysis and visual detection of offset of seismic reflections within the seismic-sag structures indicate faults and fractures are associated with many of the structures. Multi-attribute analysis highlighting chimney fluid pathways also indicates that the seismic-sag structures have a high probability for potential vertical cross-formational fluid flow along the faulted and fractured structures. A collapse of the seismic-sag structures within a deep burial setting evokes an origin related to hypogenic karst processes by ascending flow of subsurface fluids. In addition, paleo-epigenic karst related to major regional subaerial unconformities within the Florida Platform generated collapse structures (paleo-sinkholes) that are much smaller in scale than the cross-formational seismic-sag structures.

Florida

Hydrology and geomorphology of the Taiya River near the West Creek Tributary, southeast Alaska

The Taiya River flows through the Chilkoot Trail Unit of Klondike Gold Rush National Historical Park in southeast Alaska, which was founded to preserve cultural and historical resources and further understanding of natural processes active in the surrounding coastal-to-subarctic basin. Riverine processes exert an important influence on ecologically important boreal toad ( Anaxryus boreas boreas ), salmon [chum salmon ( Oncorhynchus keta ), pink salmon ( O. gorbushca ), and coho salmon ( O. kisutch )], and eulachon ( Thaleichthys pacificus ) habitats, erosion of the historic ghost town of Dyea and other cultural and historical artifacts, and recreational opportunities in the lower 7.5 kilometers (km) of the Taiya River valley bottom. Recurrent consideration of hydroelectric development in West Creek upstream of the park since the 1980s has included proposals for damming and diverting West Creek, which could alter the delivery of water and sediment to this section of the Taiya River. To improve understanding of the hydrologic dependence of park resources for the purposes of guiding effective monitoring and conservation, this study, conducted by the U.S. Geological Survey in cooperation with the National Park Service, used a review of hydrologic data, collection of discrete suspended sediment data, geomorphic mapping, and analysis of historical aerial and ground photographs in a reconnaissance of formative geomorphic processes and hydrologic conditions in the lower 7.5 km of the Taiya River valley bottom. Streamflow and suspended sediment data collected at the U.S. Geological Survey streamgages on the Taiya River and West Creek, combined with historical data, document conditions consistent with streams draining strongly glacierized basins in Alaska. Suspended sediment concentrations from samples collected concurrently over six varying flow levels during 2017–18 ranged from 6 to 284 milligrams per liter (mg/L) for the Taiya River and 13 to 162 mg/L for West Creek, which are similar to or slightly higher than historical values. For the common period of record (1970–77), correlation of daily mean discharge between the two streams was strongest (Pearson’s r = 0.97) during the prolonged May–October high-flow season and weakest ( r = 0.90) during the November–April low-flow season, when West Creek daily mean discharge was proportionally higher. For the Taiya River, streamflow data compared between the available periods of record (1970–77 and 2004–17) showed no decadal-scale patterns in mean annual discharge but did show a shift toward an earlier spring snowmelt pulse. Notable flooding in the Taiya River Basin includes glacial lake outburst floods from the Nourse River valley prior to and during the 1897–98 Gold Rush, a 2002 glacial lake outburst flood from the West Creek valley, and a 1967 rainfall-generated flood. Geomorphic mapping identified four categories of surfaces in the valley bottom—active main stem, abandoned main stem, alluvial fans, and emergent tidal surfaces. Using the maps, main-stem surfaces were subdivided into age categories to identify channel migration patterns from prior to 1940s to 2018. The valley bottom is dominated by active or abandoned channels of the Taiya River except at the extensive low-angle West Creek fan. The active main stem presently supports a mostly single-thread channel with bars and a few sloughs, but the channel actively moved and sometimes was braided within multiple, wider unvegetated corridors in 1894 and earlier. An inventory of 29 off-main-stem channels identified for the study indicates that abandoned main stem channels provide local topographic lows that can intercept groundwater or sustain tributary flow, facilitating the formation of most nonestuarine wetlands in the valley and sustaining important boreal toad breeding habitat. Within the active main stem corridor, the channel has episodically built and reworked meanders and bars, eroding more than one-half of the historic Dyea townsite, in response to glacially controlled delivery of water and sediment, flooding, inputs from West Creek, local features including large woody debris and beaver dams, and rapid uplift from isostatic rebound. West Creek has constructed a large, persistent fan, provoked kilometer-scale Taiya River channel change near the confluence, constructively added to high-season streamflow that affects Taiya River channel migration capacity, disproportionately contributed early-season streamflow, and possibly contributed to groundwater levels in the valley bottom. The progressive narrowing and stability of the main stem corridor, possibly a result of reduction in the magnitude or frequency of glacial lake outburst floods or glacial sediment delivery to streams, indicates less active future reworking of abandoned main-stem surfaces or regeneration of wetland features. The fluvial history of the Taiya River valley bottom collectively indicates continued channel change within a limited corridor, relative stability in wetland locations but uncertainty in stability of groundwater supply to them, and channel incision and extension in response to uplift.

Alaska

Mesohabitats, fish assemblage composition, and mesohabitat use of the Rio Grande silvery minnow over a range of seasonal flow regimes in the Rio Grande/Rio Bravo del Norte, in and near Big Bend National Park, Texas, 2010-11

In 2010–11, the U.S. Geological Survey (USGS), in cooperation with the U.S. Fish and Wildlife Service, evaluated the physical characteristics and fish assemblage composition of mapped river mesohabitats at four sites on the Rio Grande/Rio Bravo del Norte (hereinafter Rio Grande) in and near Big Bend National Park, Texas. The four sites used for the river habitat study were colocated with sites where the U.S. Fish and Wildlife Service has implemented an experimental reintroduction of the Rio Grande silvery minnow (Hybognathus amarus), a federally listed endangered species, into part of the historical range of this species. The four sites from upstream to downstream are USGS station 08374340 Rio Grande at Contrabando Canyon near Lajitas, Tex. (hereinafter the Contrabando site), USGS station 290956103363600 Rio Grande at Santa Elena Canyon, Big Bend National Park, Tex. (hereinafter the Santa Elena site), USGS station 291046102573900 Rio Grande near Ranger Station at Rio Grande Village, Tex. (hereinafter the Rio Grande Village site), and USGS station 292354102491100 Rio Grande above Stillwell Crossing near Big Bend National Park, Tex. (hereinafter the Stillwell Crossing site). In-channel river habitat was mapped at the mesohabitat scale over a range of seasonal streamflows. A late summer (August–September 2010) high-flow regime, an early spring (April–May 2010) intermediate flow regime, and a late spring (May 2011) low-flow regime were the seasonal flows used in the study. River habitat was mapped in the field by using a geographic information system and a Global Positioning System unit to characterize the sites at the mesohabitat scale. Physical characteristics of a subset of mesohabitats in a reach of the Rio Grande at each site were measured during each flow regime and included depth, velocity, type and size of the substrate, and percent embeddedness. Selected water-quality properties (dissolved oxygen, pH, specific conductance, and temperature) of a subset of mesohabitats were also measured. The fish assemblage composition at the four sites was determined during the three flow regimes, and fish were collected by seining in each mesohabitat where physical characteristic data were measured, except during some periods of high flow when electrofishing was done to supplement seining. The total number and number of types of mesohabitats were larger during low flows compared to intermediate flows, and larger during intermediate flows compared to high flows. Decreases in streamflow typically led to increases in channel complexity in terms of the number of different types and total number of mesohabitats present. The total wetted area increased and the number of mesohabitat types generally decreased as streamflow increased. At all four sites, the smallest depths and velocities were generally measured during low flow and the largest depths and velocities at high flow. Specific conductance was relatively consistent between the Contrabando and Santa Elena sites, the two most upstream sites. Specific conductance decreased appreciably between the Santa Elena site and the Rio Grande Village, and decreased slightly between the Rio Grande Village site and the Stillwell Crossing site. Specific-conductance values within and among mesohabitat types at a given site were relatively consistent. The pH values measured within and among mesohabitat types also were relatively consistent at all four sites. Median dissolved oxygen concentrations were relatively consistent between the Contrabando and Santa Elena sites (8.34 and 8.54 milligrams per liter [mg/L], respectively) but decreased along the stretch of river between the Santa Elena and Rio Grande Village sites to 7.31 mg/L, possibly because of small dissolved oxygen concentrations associated with contributions from springs between the Santa Elena and Rio Grande Village sites. Dissolved oxygen concentrations increased substantially between the Rio Grande Village and Stillwell Crossing sites to 10.06 mg/L. Mesohabitat water temperatures were generally highest in mesohabitats commonly associated with shallow water depths and low velocities (forewaters, backwaters, and embayments). Of the 21 species of fish collected during the three flow regimes, red shiner ( Cyprinella lutrensis ) was the most abundant species overall, accounting for about 35 percent of all fish collected. Another minnow, the endemic Tamaulipas shiner ( Notropis braytoni ), was second in overall abundance. A nonnative species, the common carp ( Cyprinus carpio ), was the third most abundant species overall. No statistically significant differences in fish-species richness were found among the different mesohabitat types. Median fish-species richness and maximum fish-species richness values were larger, and fish-species richness was more variable in runs, pools, forewaters, and backwaters during low flow compared to the fish-species richness values calculated for intermediate and high flows. Fish density in backwater mesohabitats was significantly different from fish densities in run mesohabitats, but fish densities were not significantly different among the other mesohabitat types. Of the 39 Rio Grande silvery minnow individuals collected at the four study sites, 21 (more than half) were collected at the Santa Elena site, 12 at the Contrabando site, and 3 each at the Rio Grande Village and Stillwell Crossing sites. Rio Grande silvery minnow fish-species densities followed the same order as abundance of this species at the sites; fish-species densities ranged from 0.95 fish per 100 square meters (m 2 ) at the Santa Elena site to 0.11–0.47 fish per 100 m 2 at the other three sites. The Rio Grande silvery minnow was most common in pools and runs during low- and intermediate-flow regimes. This species was less commonly collected in backwaters, embayments, and rapids, and none were collected in forewaters or submerged channel bars. The Tamaulipas shiner has similar life-history characteristics compared to the Rio Grande silvery minnow, including similar feeding habits and habitat use. Tamaulipas shiner was most common in backwater, run, and riffle mesohabitats (in decreasing order) during low and intermediate flow and was less common in submerged channel bar, pool, forewater, rapid, and embayment mesohabitats (in decreasing order) during the same flows. The overall relative percent density (composite of all three flow regimes) of Rio Grande silvery minnow was largest in rapid and pool mesohabitats and for Tamaulipas shiner was largest in backwater mesohabitats. There were no statistically significant differences between the stream velocities associated with seine hauls of the Rio Grande silvery minnow and Tamaulipas shiner. Stream velocities associated with the seine hauls that included Rio Grande silvery minnow indicate that this species is predominantly found in low-velocity mesohabitats. Velocities associated with seine hauls that included the Tamaulipas shiner represented a much broader overall range of velocities than those associated with Rio Grande silvery minnow collections. No statistically significant differences were found between the depths for seine hauls that included Rio Grande silvery minnow or Tamaulipas shiner. The Rio Grande silvery minnow was more commonly collected in seine hauls from mesohabitats dominated by cobble substrates and less frequently collected in mesohabitats with substrates dominated by fine-sized silt and clay particles, gravels, and sands, in that order. In contrast, the Tamaulipas shiner was broadly distributed among mesohabitats characterized as having gravel, cobble, and silt and clay.

Texas

Analysis and review of fishery-dependent data for Hawaiian nearshore noncommercial fisheries

Noncommercial, shore-based fisheries provide economic, social, and cultural services to communities throughout the Hawaiian Islands. The State of Hawai‘i Department of Land and Natural Resources (DLNR), Division of Aquatic Resources (DAR) routinely conducts surveys to monitor noncommercial fisheries such that estimates of fishing effort and catch by gear type can be generated and used to implement more sustainable management practices. DAR executes both the Hawai‘i Marine Recreational Fishery Survey (HMRFS), a nationally standardized survey that focuses on intercepting fishers at access points (i.e., boat ramps) across the main Hawaiian Islands, and a set of roving creel surveys on O‘ahu, Maui Nui, and Kaua‘i that observe and intercept fishers at locations along the shoreline outside of those targeted by HMRFS. The latter set of creel surveys were designed to complement HMRFS by expanding its geographic coverage and thus providing a more representative picture of noncommercial fishing in Hawai‘i. Sustainable management priorities set by DAR rely on the availability of statewide, fishery- dependent data. Thus, we collate information from island-based roving creel surveys into a cohesive Statewide Creel Survey Database. Further, we provide preliminary analyses and describe ways that surveys could be streamlined to improve future data collection, analysis, and utility. In so doing, we synthesize the most detailed information to-date about noncommercial shore-based fisheries of Hawai‘i. The unprecedented spatial and temporal coverage of DAR’s dataset reveals the value of their survey efforts over the last decade to address fishery management needs. Our primary objectives, results, and conclusions are summarized below: 1) Integrate DAR roving creel survey data from different islands into a single Statewide Creel Survey Dataset (Chapter II). We describe the collation of creel survey data from O‘ahu, Maui Nui, and Kaua‘i into a statewide dataset. We also offer ways in which these surveys could be streamlined to meet the needs of managers and decision makers. Briefly, these are to create a statewide strategic plan, standardize the execution of standard operating procedures, centralize the creel survey database and associated metadata, and consider using technology that improves the data pipeline, including transitioning from paper-based to electronic systems for data entry and processing. 2) Assess whether the new Statewide Creel Survey Dataset can provide inputs for length-based stock assessments (Chapter III). Only on Maui were interviews conducted with associated catch data. There was reasonably high taxonomic coverage (42 species from 186 interviews with 310 fishers), but low sample sizes for nearly all species precluded the development of length-based stock assessments. We provide summary statistics from the existing data and briefly discuss how technologies could be used to automate analysis of images of noncommercial catch. 3) Analyze the Statewide Creel Survey Dataset for spatial and temporal patterns in fishing effort (Chapter IV): a. Visualizing noncommercial fishing pressure . We found that fishing effort (mean number of fishers observed per survey event at a site) on O'ahu was over three times greater than that recorded during similar surveys conducted on Maui or Kaua'i. We create maps that display the distribution of angling and spearfishing effort around each of the three islands. b. Factors that predict fishing “hotspots” around Maui . Fishing effort on Maui was associated with areas with more wave power and less parking availability. There were half as many fishers in areas with parking lots than in areas with parking on the road shoulder only. c. Changes in fishing effort during the COVID-19 pandemic . There was no change in fishing effort on O‘ahu during the first year of the pandemic, but there was a 20% decline in year 2 and a 33% decline in year 3, both in comparison to pre-pandemic levels. Pre-pandemic creel survey data were unavailable for Maui and Kaua‘i, but fishing effort on these islands also declined as the pandemic progressed at similar or greater rates than those observed on O‘ahu. 4) Quantify potential bias in survey methods by experimentally deriving fisher detection probabilities of shore-based and drone-based surveys (Chapter V): a. Shore-based surveys . We conducted roving creel surveys for four months at three locations around Hilo Bay, designed to emulate and estimate the efficacy of DAR standard operating procedures. There was high agreement between paired observers in counting fishers, leading to near-perfect detection probabilities of both anglers (94%) and spearfishers (97%), but relatively low agreement and detection probabilities of other fishers (throw net, ‘opihi picking, etc.) (52%). b. Drone-based surveys . We used an unmanned aerial vehicle (UAV; operated by DAR staff) to collect imagery of fishers along the Hilo Bay shoreline. We used still images and video clips (with known fishing activity) to build an online survey that was distributed to DAR and HCFRU personnel, asking them to count and categorize resource users as a snorkeler, spearfisher, angler, or other fisher. Only 40.0% of the responses correctly counted and categorized resource users in the image. Anglers were correctly identified and enumerated in 90.0% of the responses, but the correct response rates of the other three user categories ranged from 67.8% – 79.4%. Snorkelers and anglers tended to be undercounted while spearfishers and other fishers were overcounted. 5) Review the potential for incorporating emerging technologies that will improve, augment, and evolve creel survey data collection, especially for spearfishing (Chapter VI). Within the context of monitoring shore-based noncommercial fishing, we review the use of electronic data entry/processing systems with geospatial and image capabilities, field cameras, drones, smart buoys, citizen science apps, data mining social media, artificial intelligence and machine learning. We highlight several of the challenges and considerations when implementing these technologies into creel surveys and provide a synthesis of options that could be used to better estimate spearfishing. The general conclusion of this assessment is that the DAR roving creel survey program is collecting valuable data that supplement the existing HMRFS efforts. However, there are a number of areas that could be improved to make these efforts a more effective tool for decision-making processes in resource management and conservation: 1) Establishment of clear statewide and island objectives for the Statewide Creel Survey Dataset. Currently, data collection efforts are focused towards addressing a very broad purpose – supplementing the HMRFS data collection efforts. However, the results of the preliminary analyses conducted as part of this project suggest that the data could be used to address other areas of need if these objectives were clearly defined. Further, the design of the creel survey would benefit from greater standardization of survey protocols between islands and an effort to define a) the acceptable margins of error associated with the estimates generated by these data and b) the minimum level of change that the surveys would need to detect to be useful to managers. 2) Centralization of data entry, data quality assessment, and data accessibility. Currently, each DAR office manages data entry, checks the data for errors, and is responsible for managing and storing the data. Instituting a centralized data entry system, particularly an online database that can receive survey data from tablets or smartphones running a standardized data collection application would improve efficiency, reduce data entry errors, and accelerate the availability of data to managers. A substantial amount of time and effort from the project described in this report was devoted to checking the dataset for errors. The development and application of data quality assurance protocols would ensure that the data are reliable and available in a timely fashion to support management decisions. 3) Address lingering questions regarding the efficacy of current survey protocols to capture and characterize the spearfishing component of the noncommercial fishery. The results presented in the report suggest that the current creel survey protocols do a good job detecting spearfishers when present but are not capturing sufficient data about their catch or total effort. There are also questions remaining as to whether the survey times and sites are sufficiently capturing the behavior of spearfishers in Hawai‘i. A more thorough assessment – whether through additional research, alteration of survey design, or review of data by representatives of the spearfishing community – would provide insight on how to use the Statewide Creel Survey Database to inform management of spearfishing. 4) Investigate the integration of technological advancements into the creel survey methods. As priorities and needs are developed and formalized, it would be valuable to consider how various technological advancements might enhance and streamline data collection or open new avenues of inquiry.

Hawaii

Pesticides in groundwater in the Anacostia River and Rock Creek watersheds in Washington, D.C., 2005 and 2008

The U.S. Geological Survey (USGS), in cooperation with the District Department of the Environment, conducted a groundwater-quality investigation to (a) determine the presence, concentrations, and distribution of selected pesticides in groundwater, and (b) assess the presence of pesticides in groundwater in relation to selected landscape, hydrogeologic, and groundwater-quality characteristics in the shallow groundwater underlying the Anacostia River and Rock Creek watersheds in Washington, D.C. With one exception, well depths were 100 feet or less below land surface. The USGS obtained or compiled ancillary data and information on land use (2001), subsurface sediments, and groundwater samples from 17 wells in the lower Anacostia River watershed from September through December 2005, and from 14 wells in the lower Anacostia River and lower Rock Creek watersheds from August through September 2008. Twenty-seven pesticide compounds, reflecting at least 19 different types of pesticides, were detected in the groundwater samples obtained in 2005 and 2008. No fungicides were detected. In relation to the pesticides detected, degradate compounds were as or more likely to be detected than applied (parent) compounds. The detected pesticides chiefly reflected herbicides commonly used in urban settings for non-specific weed control or insecticides used for nonspecific haustellate insects (insects with specialized mouthparts for sucking liquid) or termite-specific control. Detected pesticides included a combination of pesticides currently (2008) in use, banned or under highly restricted use, and some that had replaced the banned or restricted-use pesticides. The presence of banned and restricted-use pesticides illustrates their continued persistence and resistance to complete degradation in the environment. The presence of the replacement pesticides indicates the susceptibility of the surficial aquifer to contamination irrespective of the changes in the pesticides used. A preliminary review of the data collected in 2005 and 2008 indicated that differences in the surficial geology, land use (as a surrogate for pesticide use), and above-average precipitation for most of 2004 through 2008, as well as differences in the number and performance of USGS laboratory methods used, could have led to more pesticides detected in groundwater samples collected in 2008 than in groundwater samples collected in 2005. Thus, although data from both years of collection were used for interpretive analysis, emphasis was placed on the analysis of the data obtained in 2008. The presence of pesticides in shallow groundwater (less than approximately 100 ft (feet), or 30 m (meters), below land surface) indicated at least the upper surficial aquifer in Washington, D.C. was susceptible to contamination. One or more herbicides or insecticides were detected in groundwater samples collected from 50 percent of the shallow wells sampled in 2005, and from 62 percent of the shallow wells sampled in 2008. Differences among types of pesticides in shallow groundwater were apparent. The most frequently detected class of herbicides was the s-triazine compounds—atrazine, simazine, or prometon, or the atrazine-degradate compounds—2-chloro-4-ethylamino-6-amino-s-triazine (desethylatrazine or CIAT) and 2-chloro-4-isopropylamino-6-amino-s-triazine (hydroxyatrazine or OIET). The next most frequently detected classes of herbicides were the chloroacetanilides, including metolachlor and acetochlor, and the ureic herbicides, including diuron (and degradate, 3,4-dichloroaniline), fluometuron, metsulfuron methyl, sulfameturon, bromacil, and tebuthiuron. Insecticides also were detected, but less frequently than herbicides, with one or more insecticides present in groundwater samples from 38 percent of shallow wells sampled in 2008. Detected insecticides included parent or degradate compounds commonly used for either nonspecific or haustellate (sucking) insects, including chlorpyrifos and dichlorodiphenyldichloroethane (p,p’-DDD; a degradate of dichlorodiphenyltrichloroethane, DDT), and for termite control, including dieldrin, chlordane, heptachlor epoxide, (a degradate of heptachlor), fipronil, and the sulfone and sulfide degradates of fipronil. The concentrations of individual pesticides in shallow groundwater in both years were low. Maximum concentrations were no greater than a few tenths of a microgram per liter (μg/L); typical concentrations often were less than 0.1 μg/L. Multiple pesticides, however, commonly were present in groundwater. For example, in 2008, approximately 88 percent (7 of 8) of the wells that yielded a sample with at least one detectable pesticide contained five or more pesticides. The highest number of detections occurred in a groundwater sample from well WE Ca 32, which is located in a highly developed urban area; this sample contained 15 different pesticide residues. In relation to human and aquatic health, no pesticide concentration in either 2005 or 2008 exceeded Federal drinking-water standards. Groundwater samples from a few sites, however, contained levels of chiefly banned or restricted-use pesticides that exceeded other human-health and (or) aquatic-health guidelines. For example, concentrations of dieldrin in 2008 groundwater samples from three wells—WE Ca 32 (0.028 μg/L), WE Ba 11 (0.016 μg/L), and WW Ac 8 (0.014 μg/L)—fell within the range of concern for 2004 Federally approved non-regulatory USGS Health-Based Assessment benchmarks (0.002 to 0.2 μg/L), and exceeded earlier (1999) Federal criteria for drinking water (0.000052 μg/L). Other individual compounds whose concentrations exceeded 1999 Federal guidelines for samples from one or more of these three sites, or another site, included p,p’-DDD, dichlorodiphenyldichloroethylene (p,p’-DDE; another degradate of DDT), chlordane, and heptachlor epoxide. Pesticide concentrations in groundwater also were compared to three aquatic-health guidelines for freshwater (United States, Great Lakes, or Canada). One or more of these guidelines were exceeded in groundwater samples obtained in 2005 or 2008 for one or more of the compounds chlordane, dieldrin, heptachlor epoxide, p,p’-DDE, p,p’-DDD, and chlorpyrifos. The spatial distribution of pesticides in the shallow groundwater appeared to be related, in part, to land use, a surrogate for pesticide use. Although most of the wells sampled in this study are in parklands or other relatively open and accessible space, multiple pesticides most often were detected in 2008 groundwater samples collected from wells where a considerable percentage (in excess of 60 percent) of the land within a 500-m radius is developed space (residential, commercial, or other urban infrastructure). Insecticides were detected in wells surrounded by at least 50 percent, and most commonly by more than 80 percent, development. Well WE Ca 32, the site associated with the highest number of pesticide residues in groundwater (8 herbicides and 7 insecticides), is in a small residential park, where 99 percent of the surrounding land is well-maintained residential and commercial development. The vertical distribution of detected pesticides in shallow groundwater appeared to be related, in part, to depth below land surface, surficial-bedrock type, and differences in the chemistry of shallow groundwater. Pesticides were detected at relatively shallow depths in wells that may not have fully penetrated the shallow aquifer. For wells in which at least one pesticide was detected, the median depth below land surface to the top of the well screen was 5.8 m, and the maximum depth was 8.5 m. Among the types of surficial materials in which wells were completed—alluvium, terrace deposits, or Potomac Formation sub- or outcrops in the Coastal Plain Province, and saprolite or fractured bedrock (Laurel and Sykesville Formations) underlying saprolite in the Piedmont Province—no pesticides were detected in groundwater associated with wells completed in the alluvium or fractured bedrock. Detections occurred in some but not all wells completed in the other surficial materials. Overall, the pattern in occurrence appeared related to the local permeability of these sediments and groundwater chemistry. Groundwater with multiple pesticide detections tended to occur in permeable sediments (absent any appreciable overlying clay, silt, or clay-silt layers), in conjunction with other common urban contaminants (elevated chloride in excess of tens to hundreds of milligrams per liter (mg/L), and oxic, rather than reduced, groundwater as evidenced by elevated (in excess of 5 mg/L) concentrations of nitrate). The results of this investigation were compared to results from two other similar and recent studies on pesticide occurrence in the shallow aquifer. These included a study in the nearby Maryland and Delaware Coastal Plain Physiographic Province and one in the Maryland and Virginia Piedmont Physiographic Province. Results from these studies were similar to the current study in relation to (a) the types, frequencies, concentrations, and mixtures of pesticides detected; (b) compounds that exceeded human-and aquatic-health criteria; and (c) the occurrence and distribution of pesticides within the surficial aquifer in relation to depths, sediment types, and groundwater chemistries.

Washington D.C.

Fluvial sediment dynamics in the Shoshone River and tributaries around Willwood Dam, Park County, Wyoming

Sedimentation affects many of the aging reservoirs in the United States. Dams and water diversions from rivers have been central elements of infrastructure supporting agricultural irrigation in the arid and semiarid regions of the Western United States for more than a century. The Willwood Irrigation District diversion dam (hereafter referred to as “Willwood Dam”) in Park County, Wyoming, is approximately 12 miles northeast of Cody, Wyo.; has a structural height of 70 feet; and impounds the Shoshone River for diversion into the Willwood Canal. Willwood Dam is part of a larger irrigation scheme supported by water storage in the much larger Buffalo Bill Dam, which is approximately 20 miles upstream. In October 2016, renovation construction activities at Willwood Dam and the Willwood Canal caused an unplanned evacuation of nearly 96,000 cubic yards of fine sediment. The fine sediment release in 2016 raised concerns that ongoing sediment management at Willwood Dam could impose limits on the long-term health of the aquatic ecosystem and fish populations. The U.S. Geological Survey, in cooperation with Wyoming Department of Environmental Quality and Willwood Work Groups 2 and 3, initiated an investigation of the dynamics of sediment transport in the Shoshone River and selected tributaries between Buffalo Bill Dam and Willwood Dam. The goal of the study was to quantify sediment transport into and out of Willwood Dam on an annual, seasonal, and event basis to better understand the relative quantities of sediment coming from natural sources and human activities on the landscape. The study ran from March 2019 through October 2021 and used observations of streamflow, turbidity, and acoustic backscatter collected at streamgages upstream and downstream from Willwood Dam to quantify suspended-sediment loads into and out of the dam during irrigation and fallow seasons, precipitation-runoff events, and deliberate sediment releases. Each tributary’s relative contribution to the sediment load upstream from Willwood Dam was examined using discrete measurements of suspended-sediment concentration and bedload during irrigation and fallow seasons, precipitation events, and stable conditions. Analysis of daily precipitation and temperature data indicated that conditions in the study area during the 2019 agricultural year were wetter and colder than period of record normal, and drier and near normal temperatures for the 2020 and 2021 agricultural years. Not all sediment load records between 2019 and 2021 are complete because of rejected observations (outliers), instrument failures or fouling, and instrument removal for calibrations. Statistical modeling of suspended-sediment concentration using paired values of turbidity and acoustic backscatter produced four models that, after refinement, had coefficients of determination indicating that more than 84 percent of the variance was explained by either turbidity or acoustic backscatter. A system of rules was developed to select the model predictions based on the seasonal operations of Willwood Dam, assumptions about the grain sizes mobilized during these operations, and assumed accuracy of the models at the downstream streamgage (Shoshone River below Willwood Dam, near Ralston, Wyo. [streamgage 06284010]) under different operational conditions. The sediment budget between upstream and downstream estimates of loads was interpreted using the mean predicted values bound by their respective model prediction intervals. When mean predicted loads of one streamgage were contained in the prediction intervals of the other streamgage, and vice-versa, difference in the sediment budget were interpreted as “indeterminate.” Modeled sediment load balances demonstrated the depositional and erosional behaviors expected from the conceptual model of dam operations whereby sediment tends to accumulate during irrigation seasons when the dam is spilling over the top, and sediment tends to evacuate during the fallow seasons when it is flowing through the sluice gates at the base of the dam. The sediment load calculations using the rules-based model criteria indicated that between 14,200 and 380,000 tons of suspended sediment moved through the Shoshone River around Willwood Dam during the irrigation seasons of 2019, 2020, and 2021; 380,000 tons of suspended sediment were transported during the cool, wet year of 2019, and 14,200 tons of suspended sediment were transported in 2020, which was relatively dry. During fallow seasons 2019, 2020, and 2021, which had fewer complete records, between 1,140 and 106,000 tons of suspended sediment was estimated to have moved through the river. For all seasons except fallow season 2022, the models estimated that more sediment was released from the dam than entered the dam, but the modeled mean loads at each streamgage were nearly always within the prediction intervals of each other, making the sediment balance indeterminant. Examination of suspended-sediment loads during irrigation seasons indicated that between 65 and 85 percent of fine sediment was transported during annual high flows and storm events, with the remainder transported during steady, lower streamflows. Examination of suspended loads during fallow seasons indicated that deliberate sediment releases through Willwood Dam accounted for between 39 and 67 percent of the total sediment moved during the fallow seasons. Deliberate sediment releases from Willwood Dam had estimated net exports of between 1,360 and 22,400 tons. Between August 2017 and July 2023, suspended-sediment concentration and bedload sediment samples were collected from 9 tributaries to the Shoshone River during 137 sampling events, including stable and precipitation-runoff conditions. During irrigation season precipitation events, the mean total sediment yields ranged from 0.33 to 9.51 tons per day per square mile; during fallow season precipitation events, the mean total yields ranged from 0.04 to 0.95 ton per day per square mile. The mean total sediment yield per unit area across all samples at each tributary site ranged from 0.26 to 3.08 tons per day per square mile. Bedload was a minor fraction of the total load, constituting a mean of 4 percent across all samples; 3 and 6 percent for events and nonevents, respectively, during irrigation season; and 3 and 1 percent for events and nonevents, respectively, during the fallow season. With the exception of one tributary, Dry Creek, these mean yield values were within the range of watershed-scale background sediment yield values estimated from reservoir surveys and previous suspended-sediment studies. Imagery from irrigation seasons 2012, 2015, 2017, 2019, and 2022 was used to determine the planimetric backwater extent of the pool area in the Shoshone River behind Willwood Dam to identify any changes in sediment storage. Active river channel widths in the Shoshone River upstream from Willwood Dam were all similar between years except 2015, which was determined to be statistically different from all other years. Bathymetric data taken in the pool behind Willwood Dam during three different surveys between November 2017 and April 2022 indicated no statistically significant differences in bed elevations between the years. Results from the planimetric and bathymetric survey data provide multiple lines of evidence indicating that sediment did not accumulate behind the dam within the error of the methods used. Examination of how precipitation affects sediment transport in the Shoshone River upstream from Willwood Dam indicated that accumulated rainfall from the natural runoff events captured during the study period varied from a trace to as much as 4.26 inches, with associated predicted suspended-sediment loads varying from 112 to 232,000 tons of suspended sediment. The behavior of the sediment loads relative to accumulated precipitation did not appear to change depending on irrigation or fallow season. A model of suspended-sediment concentrations relative to the 2-day accumulated precipitation indicated that suspended-sediment concentrations in the Shoshone River upstream from Willwood Dam increased exponentially for accumulations of 0.3 inch or more; such storms accounted for 10 percent or less of precipitation events observed during the 1981 to 2018 period of record. The gaps in records, precision of the instrumentation, and large variation in grain sizes in suspended-sediment mixtures downstream from the dam made closing the sediment budgets for most seasons unattainable. The biggest recent change in sediment storage measured using the planimetric area of deposits behind Willwood Dam took place between 2015 and 2017. The main event between these two measurements was the installation of new Willwood Canal gates in October 2016, which resulted in the large unplanned sediment release. Because the sediment budgets were nearly always indeterminate and the planimetric and bathymetric data indicated little change in the bed and bank material, it is likely that the change in sediment storage behind the dam during the study period was small relative to the precision of the statistical models and other uncertainties. This body of evidence suggests that, averaged during the 3-year study period, no major changes in storage took place, and that the current operations may be keeping storage at near-equilibrium. This condition could have been initiated because the middle sluice gate has now been operational since 2014, and the sediment release in October 2016 evacuated a large amount of legacy sediment from storage. Although the uncertainties are large, sluicing events allow for controlled releases of sediment that contributed to the near equilibrium conditions observed over an annual basis during this study.

Wyoming