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At least 1,279 records · Page 71Linked to original sources

Inventory of gate-sensing equipment at 14 U.S. Army Corps of Engineers dams in Texas

The U.S. Army Corps of Engineers (USACE) is a worldwide organization that provides engineering services, environmental restoration, and construction support for a wide variety of civil and military projects. The primary civil mission of the USACE is developing and managing the Nation's water resources. USACE develops projects to reduce flood damage, improve navigation channels and harbors, protect wetlands, and preserve, safeguard, and enhance the environment. Additional missions of the Corps include managing federal real estate, assisting communities with emergency operations and recovery, and providing recreation opportunities. Accurate and timely information on reservoir gate openings is critical for managing flood pools, reducing flood damage downstream from reservoirs, delivering drinking-water supplies, and meeting an assortment of competing downstream water-use needs. Documentation, operation, and maintenance of gate sensors are needed so that reliable, timely information is available to USACE to make reservoir operation decisions. USACE requested that the U.S. Geological Survey (USGS) prepare an inventory and documentation of existing gate-sensing equipment at 14 reservoirs that will serve as a user’s manual for operating the equipment. The 14 reservoirs include Aquilla Lake, Bardwell Lake, Benbrook Lake, Canyon Lake, Georgetown Lake, Granger Lake, Grapevine Lake, Jim Chapman Lake, Joe Pool Lake, Lake O’ the Pines, Ray Roberts Lake, Somerville Lake, Stillhouse Hollow Lake, and Wright Patman Lake. This report presents the inventory and documentation of the existing gate-sensing equipment at the 14. The report is organized by lake; information in each lake section includes location of lake and intake structure, directions to each lake (road log), access, equipment description, operation and maintenance information, job hazard analysis, wiring diagrams, photographs, and datalogger programs. The report also includes a list of contact information for the different manufacturers of equipment in service at the lakes.

Texas↗

Summary report of responses of key resources to the 2000 Low Steady Summer Flow experiment, along the Colorado River downstream from Glen Canyon Dam, Arizona

In the spring and summer of 2000, a series of steady discharges of water from Glen Canyon Dam on the Colorado River were used to evaluate the effects of aquatic habitat stability and water temperatures on native fish growth and survival, with a special focus on the endangered humpback chub (Gila cypha), downstream from the dam in Grand Canyon. The steady releases were bracketed by peak powerplant releases in late-May and early-September. The duration and volume of releases from the dam varied between spring and summer. The intent of the experimental hydrograph was to mimic predam river discharge patterns by including a high, steady discharge in the spring and a low, steady discharge in the summer. The hydrologic experiment was called the Low Steady Summer Flow (LSSF) experiment because steady discharges of 226 m3/s dominated the hydrograph for 4 months from June through September 2000. The experimental hydrograph was developed in response to one of the U.S. Fish and Wildlife Service's Recommended and Prudent Alternatives (RPA) in its Biological Opinion of the Operation of Glen Canyon Dam Final Environmental Impact Statement. The RPA focused on the hypothesis that seasonally adjusted steady flows were dam operations that might benefit humpback chub more than the Record of Decision operations, known as Modified Low Fluctuating Flow (MLFF) operations. Condensed timelines between planning and implementation (2 months) of the experiment and the time required for logistics, purchasing, and contracting resulted in limited data collection during the high-release part of the experiment that occurred in spring. The LSSF experiment is the longest planned hydrograph that departed from the MLFF operations since Record of Decision operations began in 1996. As part of the experiment, several studies focused on the responses of physical properties related to environments that young-of-year (YOY) native fish might occupy (for example, measuring mainstem and shoreline water temperature, and quantifying useable shorelines). The part of the hydrograph that included a habitat maintenance flow (a 4-day spike at a powerplant capacity of 877 m3/s) and sustained high releases in April and May (averaging 509 m3/s) resulted in sediment export to Lake Mead, the reservoir downstream from Glen Canyon Dam, which is outside the study area. Some mid-elevation sandbar building (between 566 and 877 m3/s stage elevations) occurred from existing sediment deposits rather than from sediment inputs from tributaries during the previous winter. Low releases in the summer combined with low tributary sediment inputs resulted in minor sediment accumulation in the study area. The September habitat maintenance flow reworked accumulated sediment and resulted in increases in the area of some backwaters. The mainstem water temperatures in the reach near the Little Colorado River during the LSSF experiment varied little from previous years. Mainstem water temperatures in western Grand Canyon average 17 to 20 degrees C. During the LSSF, backwaters warmed more than other shoreline environments during the day, but most backwaters returned to mainstem water temperatures overnight. Shoreline surface water temperatures from river mile (RM) 30 to 72 varied between 9 and 28 degrees C in the middle of the day in July. These temperatures are within the optimal temperature range for humpback chub growth and spawning, which is between 15 and 24 degrees C. How surface water temperatures transfer to subsurface water temperatures is unknown. Data collection associated with the response of fish to the 2000 LSSF hydrograph focused on fish growth and abundance along the Colorado River in Grand Canyon. The target resource, humpback chub and other native fishes, did not respond in a strongly positive or strongly negative manner to the LSSF hydrograph during the sampling period, which extended from June to September 2000. In 2000, the mean total length of YOY native fishes was similar to the mean

Arizona↗

Nearshore thermal gradients of the Colorado River near the Little Colorado River confluence, Grand Canyon National Park, Arizona, 2010

Construction and operation of Glen Canyon Dam has dramatically impacted the flow of the Colorado River through Glen, Marble, and Grand Canyons. Extremes in both streamflow and water temperature have been suppressed by controlled releases from the dam. Trapping of sediment in Lake Powell, the reservoir formed by Glen Canyon Dam, has also dramatically reduced the supply of suspended sediment entering the system. These changes have altered the riverine ecosystem and the habitat of native species, including fish such as the endangered humpback chub ( Gila cypha ). Most native fish are adapted to seasonally warm water, and the continuous relatively cold water released by the dam is one of the factors that is believed to limit humpback chub growth and survival. While average mainstem temperatures in the Colorado River are well documented, there is limited understanding of temperatures in the nearshore environments that fish typically occupy. Four nearshore geomorphic unit types were studied between the confluence of the Colorado and Little Colorado Rivers and Lava Canyon in the summer and fall of 2010, for study periods of 10 to 27 days. Five to seven sites were studied during each interval. Persistent thermal gradients greater than the 0.2 °C accuracy of the instruments were not observed in any of the sampled shoreline environments. Temperature gradients between the shoreline and mainstem on the order of 4 °C, believed to be important to the habitat-seeking behavior of native or nonnative fishes, were not detected.

Arizona;Nevada;Utah↗

Science needs for determining the effects of climate change on harmful algal blooms in the southeastern United States

The Southeastern United States has many lakes, streams, and reservoirs that serve as important drinking water sources with recreational, agricultural, and ecological uses. However, harmful algal blooms (HABs) are becoming more common in these waters, causing health issues for humans and animals. HABs have been listed as a contaminant of emerging concern, and the magnitude, frequency, and duration of HABs appear to be increasing at the global scale. While it is well known that nutrients stimulate algae growth, it is not clear how climate change and other parameters stimulate the development of toxin production by HABs. The scientific literature describes parameters, such as storm occurrence, temperature, dissolved metals, erosion of soils, increasing length of growing season, discharge, and hydroperiod, that may affect algae growth and toxin production. Climate and hydrologic models address many of the physical and environmental parameters that influence HABs, but no climate models directly address HABs. This report compiles information from the existing literature pertaining to HABs and the modeling and forecasting of HABS. This compilation is done through the incorporation of climate change models. HAB research that involves climate change will require multiple disciplines that bring together ecologists, hydrologists, climatologists, engineers, economists, and new technology. Resource managers could use geographic data about the occurrence and distribution of HABs to develop models that identify waterbodies more vulnerable to HAB events. Development of such models will require teams capable of integrating biological, chemical, and physical factors. Model development will require additional research that can resolve anthropogenic and climate-related environmental factors to identify trends in freshwater HABs. The complexity and interconnectedness of the parameters that influence HAB occurrences will make model development challenging and require rigorous regional calibration.

Open-File Report↗

Projected effects of proposed salinity-control projects on shallow ground water; preliminary results for the upper Brazos River basin, Texas

As part of the plan to control the natural salt pollution in the upper Brazos River basin of Texas, the U.S. Army Corps of Engineers recommended construction of three impoundment and retention reservoirs. In connection with the proposed reservoirs, the U.S. Geological Survey was requested to define the existing ground-water conditions in the shallow ground-water system of the area and to project the post-construction effects of the reservoirs on the shallow aquifer, especially in relation to aquifer-head changes but also with respect to possible changes in the chemical quality of the ground water. The Corps of Engineers' plan includes a total impoundment reservoir (Kiowa Peak Lake on North Croton Creek) with more than 170,000 acre-feet of storage at the 100-year average pool altitude of 1,550 feet. Croton Lake (23,000 acrefeet of storage at the 100-year average pool altitude of 1,760 feet) on Croton Creek and Dove Lake (no permanent storage) on Salt Croton Creek are projected to hold salt water for transfer to the large Kiowa Peak Lake. The aquifer in the project area is a shallow water-table system with relatively fresh water (calcium sulfate type), in comparison to the saline streamflow, and contains 2,000 to 5,000 milligrams per liter of dissolved solids. The aquifer consists of Permian rocks with very small permeability and is separated from an even less perneable and deeper brine system (sodium chloride type of up to 200,000 milligrams per liter of dissolved solids) by a thin transition zone. Small quantities of infiltration from precipitation in the drainage area constitute the recharge to the aquifer. Discharge from the aquifer consists of the base flow along creeks; well discharge is negligible. Two-dimensional digital-computer models were developed for aquifer simulation of steady and transient conditions in which the density effects of salt water are considered. The models were used to project the effects of the 100- year impoundment of salt water in Kiowa Peak Lake and Croton Lake on the freshwater system. Rises in aquifer head of 10 to 50 feet are projected only for areas near each dan and along each lake shoreline. The maximum migration of salt water downstream from each dam is projected to be about 1 mile. The modeling efforts in this study did not include the effects of hydrodynamic dispersion nor consideration of possible changes in the hydraulic conductivity of the aquifer due to physical and chemical interactions in the salt-water and fresh-water environments.

Open-File Report↗

Surficial geologic map of the Spirit Mountain SE and part of the Spirit Mountain NE 7.5' quadrangles, Nevada and Arizona

This geologic map includes a trove of stratigraphic and geomorphic information that chronicles the inception and evolution of the lower Colorado River. The map area is located near the south end of the Lake Mead National Recreation Area about 80 km (50 mi) downstream from Hoover Dam. It spans parts of northwestern Arizona and southern Nevada near the south end of Cottonwood Valley. The map includes the Spirit Mountain SE 7.5' quadrangle and the southern part of the Spirit Mountain NE 7.5' quadrangle. The map area contains well-exposed Neogene and Quaternary strata and associated geomorphic features that record and are critical in dating the arrival of the Colorado River in the early Pliocene and the subsequent history of the river and its landscape through the Holocene. The valley is bounded on the west by the Newberry Mountains (Nevada) and on the east by the Black Mountains (Arizona) and includes part of Lake Mohave, a reservoir created by the completion of Davis Dam in 1951. This map does not include the geology of the reservoir floor and focuses only on surficial deposits.

Arizona, Nevada↗

Estimated water use in Montana in 2000

The future health and economic welfare of Montana's population is dependent on a continuing supply of fresh water. Montana's finite water resources are being stressed by increasing water withdrawals and instream-flow requirements. Various water managers in Montana need comprehensive, current, and detailed water-use data to quantify current stresses and estimate and plan for future water needs. This report summarizes selected water-use data for all of Montana's counties and stream basins to help meet those needs. In 2000, the citizens of Montana withdrew and used about 10,749 million gallons per day (Mgal/d) of water from Montana's streams and aquifers. Withdrawals from surface water were about 10,477 Mgal/d and withdrawals from ground water were about 272 Mgal/d. Agricultural irrigation accounted for about 10,378 Mgal/d or about 96.5 percent of total withdrawals for all uses. Withdrawals for public supply were about 136 Mgal/d, self-supplied domestic withdrawals were about 23 Mgal/d, self-supplied industrial withdrawals were about 61 Mgal/d, withdrawals for thermoelectric power generation were about 110 Mgal/d, and withdrawals for livestock were about 41 Mgal/d. Total consumptive use of water in 2000 was about 2,370 Mgal/d, of which about 2,220 Mgal/d (93.6 percent) was for agricultural irrigation. Instream uses of water included hydroelectric power generation and maintenance of instream flows for conservation of wildlife and aquatic life, and for public recreational purposes. In 2000, about 74,486 Mgal/d was used at hydroelectric plants for generation of about 11,591 gigawatt-hours of electricity. Evaporation from large water bodies, although not a classified water use, accounts for a large loss of water in some parts of the State. Net evaporation from Montana's 60 largest reservoirs and regulated lakes averaged about 891 Mgal/d.

Scientific Investigations Report↗

Sources, fate, and transport of nitrogen and phosphorus in the Chesapeake Bay watershed: An empirical model

Spatially Referenced Regression on Watershed Attributes (SPARROW) was used to provide empirical estimates of the sources, fate, and transport of total nitrogen (TN) and total phosphorus (TP) in the Chesapeake Bay watershed, and the mean annual TN and TP flux to the bay and in each of 80,579 nontidal tributary stream reaches. Restoration efforts in recent decades have been insufficient to meet established standards for water quality and ecological conditions in Chesapeake Bay. The bay watershed includes 166,000 square kilometers of mixed land uses, multiple nutrient sources, and variable hydrogeologic, soil, and weather conditions, and bay restoration is complicated by the multitude of nutrient sources and complex interacting factors affecting the occurrence, fate, and transport of nitrogen and phosphorus from source areas to streams and the estuary. Effective and efficient nutrient management at the regional scale in support of Chesapeake Bay restoration requires a comprehensive understanding of the sources, fate, and transport of nitrogen and phosphorus in the watershed, which is only available through regional models. The current models, Chesapeake Bay nutrient SPARROW models, version 4 (CBTN_v4 and CBTP_v4), were constructed at a finer spatial resolution than previous SPARROW models for the Chesapeake Bay watershed (versions 1, 2, and 3), and include an updated timeframe and modified sources and other explantory terms. Chesapeake Bay receives an estimated 1.32 x 10 8 kilograms (132,000 metric tons) of nitrogen and 9.74 x 10 6 kilograms (9,740 metric tons) of phosphorus annually from its watershed, mainly through its two largest tributaries, the Susquehanna and Potomac Rivers. Significant (α=0.10) sources of nutrients to streams in the watershed include fertilizer and manure applications in agricultural areas, undifferentiated urban activities, point sources, atmospheric deposition and direct fixation by crops (for nitrogen), and mineral sources (for phosphorus). Agriculture (primarily fertilizer applications and crop fixation) contributes more than half of the nitrogen delivered from the watershed to the bay; phosphorus contributions are more mixed, and fairly evenly distributed among agricultural (fertilizer and manure applications) and urban (including point) sources. Natural mineral dissolution contributes approximately 14 percent of the phosphorus flux from the watershed to the Chesapeake Bay. Empirical estimates of average yields from different source areas and of the portion of selected applications delivered to streams agree closely with previously reported values in the literature. Nutrient fate and transport through the Chesapeake Bay watershed to the bay reflect the diferent physical and chemical properties of nitrogen and phosphorus compounds. Groundwater is an important pathway for nitrogen transport (as nitrate), and TN flux is greatest in areas with greater groundwater flow and in areas of the Piedmont underlain by carbonate rocks. TN flux decreases with increasing vegetative growth (likely indicative of plant uptake) and soil available water capacity (likely indicative of reducing conditions). Phosphorus transport to streams, conversely, is greatest in areas most likely to generate overland runoff and related erosion, including those with less permeable and more erodible soils and greater precipitation. Phosphorus transport also is greater in the Coastal Plain than in other areas, possibly due to saturation of soils with historical phosphorus applications. Both nitrogen and phosphorus are lost within watershed impoundments (lakes, ponds, or reservoirs), and nitrogen is also lost significantly along flowing reaches, particularly in small streams and in larger streams in warmer areas.

Chesapeake Bay↗

Water resources data for Hawaii and other Pacific areas, water year 1982: Volume 2. Guam, Northern Mariana Islands, Federated States of Micronesia, Palau, and American Samoa

Volume 2 of water resources data for the 1982 water year for other Pacific areas consist of records of stage, discharge, and water quality of streams and springs; stage of a lake and a reservoir; and water levels and water quality in wells. This report contains discharge records for 43 gaging stations; stage only record for 2 gaging stations; water quality for 1 gaging station, 36 partial-record stations; water temperature for 42 gaging stations; and water levels for 14 observation wells and water quality for 52 ground-water sites. Also included are 43 low-flow partial-record stations. Additional water data were collected at various sites, not part of the systematic data collection program, and are published as miscellaneous measurements. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating Governments and Federal agencies in other Pacific areas.

American Samoa, Guam↗

Water resources data for Hawaii and other Pacific areas, water year 1984: Volume 2. Guam, Northern Mariana Islands, Federated States of Micronesia, Palau, and American Samoa

Volume 2 of water resources data for the 1984 water year for other Pacific areas consists of records of stage, discharge, and water quality of streams and springs; stage of 2 lakes and a reservoir; and water levels and water quality in wells. This report contains discharge records for 32 gaging stations; stage only record for 3 gaging stations; water quality for 14 gaging stations; 14 partial-record stations; water temperature for 32 gaging stations; and water levels for 37 observation wells and water quality for 113 ground-water sites. Also included are 19 low-flow partial-record stations. Additional water data were collected at various sites, not part of the systematic data collection program, and are published as miscellaneous measurements. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating Governments and Federal agencies in other Pacific areas.

Hawaii↗

Water resources data for Hawaii and other Pacific areas, water year 1985: Volume 2. Guam, Northern Mariana Islands, Federated States of Micronesia, Palau, and American Samoa

Volume 2 of water resources data for the 1985 water year for other Pacific areas consists of records of stage, discharge, and water quality of streams and springs; stage of 2 lakes and a reservoir; and water levels and water quality in wells. This report contains discharge records for 31 gaging stations; stage only record for 3 gaging stations; water quality for 8 gaging stations; 6 partial-record stations; water temperature for 31 gaging stations; and water levels for 35 observation wells and water quality for 110 ground-water sites. Also included are 19 low-flow partial-record stations. Additional water data were collected at various sites, not part of the systematic data collection program, and are published as miscellaneous measurements. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating Governments and Federal agencies in other Pacific areas.

Hawaii↗

Metals transport in the Sacramento River, California, 1996-1997; Volume 2: Interpretation of metal loads

Metals transport in the Sacramento River, northern California, from July 1996 to June 1997 was evaluated in terms of metal loads from samples of water and suspended colloids that were collected on up to six occasions at 13 sites in the Sacramento River Basin. Four of the sampling periods (July, September, and November 1996; and May-June 1997) took place during relatively low-flow conditions and two sampling periods (December 1996 and January 1997) took place during high-flow and flooding conditions, respectively. This study focused primarily on loads of cadmium, copper, lead, and zinc, with secondary emphasis on loads of aluminum, iron, and mercury. Trace metals in acid mine drainage from abandoned and inactive base-metal mines, in the East and West Shasta mining districts, enter the Sacramento River system in predominantly dissolved form into both Shasta Lake and Keswick Reservoir. The proportion of trace metals that was dissolved (as opposed to colloidal) in samples collected at Shasta and Keswick dams decreased in the order zinc ≈ cadmium > copper > lead. At four sampling sites on the Sacramento River--71, 256, 360, and 412 kilometers downstream of Keswick Dam--trace-metal loads were predominantly colloidal during both high- and low-flow conditions. The proportion of total cadmium, copper, lead, and zinc loads transported to San Francisco Bay and the Sacramento-San Joaquin Delta estuary (referred to as the Bay-Delta) that is associated with mineralized areas was estimated by dividing loads at Keswick Dam by loads 412 kilometers downstream at Freeport and the Yolo Bypass. During moderately high flows in December 1996, mineralization-related total (dissolved + colloidal) trace-metal loads to the Bay-Delta (as a percentage of total loads measured downstream) were cadmium, 87 percent; copper, 35 percent; lead, 10 percent; and zinc, 51 percent. During flood conditions in January 1997 loads were cadmium, 22 percent; copper, 11 percent; lead, 2 percent; and zinc, 15 percent. During irrigation drainage season from rice fields (May-June 1997) loads were cadmium, 53 percent; copper, 42 percent; lead, 20 percent; and zinc, 75 percent. These estimates must be qualified by the following factors: (1) metal loads at Colusa in December 1996 and at Verona in May-June 1997 generally exceeded those determined at Freeport during those sampling periods. Therefore, the above percentages represent maximum estimates of the apparent total proportion of metals from mineralized areas upstream of Keswick Dam; and (2) for logistics reasons, the Sacramento River was sampled at Tower Bridge instead of at Freeport during January 1997. Available data suggest that trace metal loads from agricultural drainage may be significant during certain flow conditions in areas where metals such as copper and zinc are added as agricultural amendments. Copper loads for sampling periods in July and September 1996 and in May-June 1997 show increases of dissolved and colloidal copper and in colloidal zinc between Colusa and Verona, the reach of the Sacramento River along which the Colusa Basin Drain, the Sacramento Slough, and other agricultural return flows are tributaries. Monthly sampling of these two agricultural drains by the USGS National Water-Quality Assessment Program shows seasonal variations in metal concentrations, reaching maximum concentrations of 4 to 6 micrograms per liter in "dissolved" (0.45-micrometer filtrate) copper concentrations in May 1996, December 1996, and June 1997. The total (dissolved plus colloidal) load of copper from the Colusa Basin Drain in June 1997 was 18 kilograms per day, whereas the copper load in Spring Creek, which drains the inactive mines on Iron Mountain, was 20 kilograms per day during the same sampling period. For comparison, during the January 1997 flood, the copper load in Spring Creek was about 1,100 kilograms per day and the copper load in the Yolo Bypass was about 7,300 kilograms per day. The data clearly indicate that most copper and zinc loads during the January 1997 flood entered the Sacramento River upstream of Colusa, and upstream of the influence of the most intense agricultural drainage return flows in the Sacramento River watershed. This study has demonstrated that some trace metals of environmental significance (cadmium, copper, and zinc) in the Sacramento River are transported largely in dissolved form at upstream sites (below Shasta Dam, below Keswick Dam, and at Bend Bridge) proximal to the mineralized areas of the West Shasta and East Shasta mining districts. In contrast, these trace metals are transported largely in colloidal form at downstream sites (Colusa, Verona, Freeport, and Yolo Bypass). Aluminum, iron, and lead were observed to be transported predominantly in the colloidal phase at all mainstem Sacramento River sampling sites during all sampling periods in this study. Despite continuous water treatment, which has removed 85 to 90 percent of the cadmium, copper, and zinc from the mine drainage at Iron Mountain, Spring Creek remains a significant source of these metals to the Sacramento River system.

California↗

Method of estimating natural recharge to the Edwards Aquifer in the San Antonio area, Texas

The method of estimating annual recharge is based on data collected from a network of stream-gaging stations and on assumptions related to applying the runoff characteristics from gaged areas to ungaged areas. The basic approach is a water-balance equation, in which recharge within a stream basin is the difference between measured streamflow above and below the infiltration area of the aquifer plus the estimated runoff in the zone that includes the infiltration area. Recharge in the Medina River basin also includes seepage losses from Medina Lake and Diversion Reservoir. The principal errors in the estimates of annual recharge are related to errors in estimating runoff in ungaged areas, which represent about 30 percent of the infiltration area. The estimated long-term average annual recharge in each basin, however, is probably representative of the actual recharge because the averaging procedure tends to cancel out the major errors.

Texas↗

Land use, organochlorine compound concentrations, and trends in benthic-invertebrate communities in selected stream basins in Chester County, Pennsylvania

Land use was analyzed for the drainage areas of 26 stream sites in Chester County, Pa., that cover a total area of 227 square miles or about 30 percent of the country. The most significant land-use changes during 1967-87 were decreased agricultural land use, increased residential land use, and increased commercial and industrial land use. Bulk samples of stream-bottom materials were collected at 42 sites in the study area from October 1985 through November 1987 and analyzed for content of organochlorine pesticides and polychlorinated biphenyls (PCB's). Organochlorine compounds and (or) PCB's were detected in streambed materials collected at 40 of the 42 sites sampled. The most enriched compounds (greater than 15 micrograms per kilogram) were PCB's, chlordane, and DDT plus its breakdown products. Data suggest that chlordane residues are closely associated with residential land use. PCB residues are closely associated with industrial and commercial land use. Cores of labeled sediments from the site of Icedale Lake, a drained reservoir on the West Branch Brandywine Creek, indicate that DDT was the first organochlorine pesticide to enter the Brandywine Creek; concentrations peaked in the late 1940's and early 1950's. As DDT influx subsequently decreased, influxes of chlordane and dieldrin increased and peaked in the mind-1960's, before the Chester County biological monitoring program. Influx of all pesticides appears to have decreased significantly since the 1960's. Contingency analyses showed that the relation between the Kendall slope estimator for trend and the increases in residential land use of 12 percent or greater were significant at the 95-percent confidence level. The contingency tables also showed that the relation between diversity indices of less than 2.25 and organochlorine-compound concentrations greater than 45 micrograms per kilogram was significant at the 95-percent confidence level.

Water-Resources Investigations Report↗

Metals transport in the Sacramento River, California, 1996-1997; volume 1: Methods and data

Metals transport in the Sacramento River, northern California, was evaluated on the basis of samples of water, suspended colloids, streambed sediment, and caddisfly larvae that were collected on one to six occasions at 19 sites in the Sacramento River Basin from July 1996 to June 1997. Four of the sampling periods (July, September, and November 1996; and May-June 1997) took place during relatively low-flow conditions and two sampling periods (December 1996 and January 1997) took place during high-flow and flooding conditions; respectively. Tangential-flow ultrafiltration with 10,000 nominal molecular weight limit, or daltons (0.005 micrometer equivalent), pore-size membranes was used to separate metals in streamwater into ultrafiltrate (operationally defined dissolved fraction) and retentate (colloidal fraction) components, respectively. Conventional filtration with capsule filters (0.45 micrometer pore-size) and membrane filters (0.40 micrometer pore-size) and total-recoverable analysis of unfiltered (whole-body) samples were done for comparison at all sites. Because the total-recoverable analysis involves an incomplete digestion of particulate matter, a more reliable measurement of whole-water concentrations is derived from the sum of the dissolved component that is based on the ultrafiltrate plus the suspended component that is based on a total digestion of colloid concentrates from the ultra-filtration retentate. Metals in caddisfly larvae were determined for whole-body samples and cytosol extracts, which are intercellular solutions that provide a more sensitive indication of the metals that have been bioaccumulated. Trace metals in acidic, metal-rich drainage from abandoned and inactive sulfide mines were observed to enter the Sacramento River system (specifically, into both Shasta Lake and Keswick Reservoir) in predominantly dissolved form, as operationally defined using ultrafiltrates. The predominant source of acid mine drainage to Keswick Reservoir is Spring Creek, which drains the Iron Mountain mine area. Copper concentrations in filtered samples from Spring Creek taken during December 1996, January 1997, and May 1997 ranged from 420 to 560 micrograms per liter. Below Keswick Dam, copper concentrations in conventionally filtered samples ranged from 0.5 micrograms per liter during September 1996 to 9.4 micrograms per liter during January 1997; the latter concentration exceeded the applicable water-quality standard. The proportion of trace metals that was dissolved (versus colloidal) in samples collected at Shasta and Keswick dams decreased in the order cadmium zinc > copper > aluminum iron lead mercury. At four sampling sites on the Sacramento River at various distances downstream of Keswick Dam (Bend Bridge, 71 kilometers; Colusa, 256 kilometers; Verona, 360 kilometers; and Freeport, 412 kilometers) concentrations of these seven metals were predominantly colloidal during both high- and low-flow conditions. Because copper compounds are used extensively as algaecides in rice farming, agricultural drainage at the Colusa Basin Drain was sampled in June 1997 during a period shortly after copper applications to newly planted rice fields. Copper concentrations ranged from 1.3 to 3.0 micrograms per liter in filtered samples and from 12 to 13 micrograms per liter in whole-water samples (total recoverable analysis). These results are consistent with earlier work by the U.S. Geological Survey indicating that copper in rice-field drainage likely represents a detectable, but relatively minor source of copper to the Sacramento River. Lead isotope data from suspended colloids and streambed sediments collected during October and November 1996 indicate that lead from acid mine drainage sources became a relatively minor component of the total lead at the site located 71 kilometers downstream of Keswick Dam and beyond. Cadmium, copper, and zinc concentrations in caddisfly larvae were elevated at several sites downstream of Keswick Dam, but concentrations of aluminum, iron, lead, and mercury were relatively low, especially in the cytosol extracts. Cadmium showed the highest degree of bioaccumulation in whole-body and cytosol analyses, relative to an unmineralized control site (Cottonwood Creek). Cadmium bioaccumulation persisted in samples collected as far as 118 kilometers downstream of Keswick Dam, consistent with transport in a form more bioavailable than lead.

California↗

The floods of March 1936, part 1, New England rivers

During the period March 9-22, 1936, there occurred in close succession over the northeastern United States, from the James and upper Ohio River Basins in Virginia and Pennsylvania to the river basins of Maine, two extraordinarily heavy storms, in which the precipitation was almost entirely in the form of rain. The depths of rainfall mark this period as one of the greatest concentrations of precipitation, in respect to time and magnitude of the area covered, of which there is record in this country. At the time of the rain there were also accumulations of snow on the ground over much of the storm-affected region that were large for the season. The comparatively warm temperatures associated with the storms thawed the snow and added materially to the quantities of water to be disposed of by drainage into the waterways, by surface storage in lakes, ponds, and reservoirs, by absorption in the ground, and, probably in comparatively negligible degree, by evaporation. The total quantity of water that had to be disposed of in these ways ranged between 10 and 30 inches in depth over much of the region. The water disposed of by natural storage, absorption, and evaporation amounted to average depths over the many river basins generally within the range of 1 to 3 inches, with a significant degree of uniformity and systematic areal distribution. The remainder of the rain and snow water, generally much larger or even several times larger in amount than surface storage, absorption, and evaporation, required accommodation by the channels of the brooks, creeks, and rivers. There were generally two distinct flood peaks, and in many of the basins the destruction was seriously aggravated, especially during the first flood, by the break-up of thick ice cover accumulated through a winter of exceptionally continuous and severe cold weather. The resulting floods were extraordinarily severe, and records of river stages, extending on some streams back to or nearly to the time of settlement by white men, were broken many of them by wide margins. The peak of the Connecticut River at Hartford, Conn., was 8.6 feet higher than had been experienced since the settlement by white men, 300 years ago. The Susquehanna River at Harrisburg, Pa., was 3.5 feet higher than had been known in a period of record covering about 200 years. The Ohio River at Pittsburgh, Pa., was 6.1 feet higher than had been known in the period beginning 1762. This volume presents many of the facts of these notable floods with respect to the New England rivers, for permanent record and for study and reference by engineers concerned with the building of highways, bridges, and industrial plants, planners of river development, and others. Similar volumes for the region from the Hudson River to the Susquehanna River and for the Potomac, James, and upper Ohio River Basins are presented in companion Water-Supply Papers 799 and 800 respectively. In this volume records of stage and discharge for the period Including the floods are presented for about 150 measurement stations; peak discharges with comparative data for other floods at more than 400 measurement points are summarized; crest stages along an aggregate length of stream channel of 2,820 miles are tabulated; and results of detailed studies of the rainfall and run-off and many other kinds of flood information are presented.

Water Supply Paper↗

The floods of March 1936, part 2, Hudson River to Susquehanna River region

During the period March 9-22, 1936, there occurred in close succession over the northeastern United States, from the James and upper Ohio River Basins in Virginia and Pennsylvania to the river basins of Maine, two extraordinarily heavy storms, in which the precipitation was almost entirely in the form of rain. The depths of rainfall mark this period as one of the greatest concentrations of precipitation, in respect to time and magnitude of the area covered, of which there is record in this country. At the time of the rain there were also accumulations of snow on the ground over much of the storm-affected region that were large for the season. The comparatively warm temperatures associated with the storms thawed the snow and added materially to the quantities of water to be disposed of by drainage into the waterways, by surface storage in lakes, ponds, and reservoirs, by absorption in the ground, and, probably in comparatively negligible degree, by evaporation. The total quantity of water that had to be disposed of in these ways ranged between 10 and 30 inches in depth over much of the region. The water disposed of by natural storage, absorption, and evaporation amounted to average depths over the many river basins generally within the range of 1 to 3 inches, with a significant degree of uniformity and systematic areal distribution. The remainder of the rain and snow water, generally much larger or even several times larger in amount than surface storage, absorption, and evaporation, required accommodation by the channels of the brooks, creeks, and rivers. There were generally two distinct flood peaks, and in many of the basins the destruction was seriously aggravated, especially during the first flood, by the break-up of thick ice cover accumulated through a winter of exceptionally continuous and severe cold weather. The resulting floods were extraordinarily severe, and records of river stages, extending on some streams back to or nearly to the time of settlement by white men, were broken many of them by wide margins. The peak of the Connecticut River at Hartford, Conn., was 8.6 feet higher than had been experienced since the settlement by white men, 300 years ago. The Susquehanna River at Harrisburg, Pa., was 3.5 feet higher than had been known in a period of record covering about 200 years. The Ohio River at Pittsburgh, Pa., was 6.1 feet higher than had been known in the period beginning 1762. This volume presents many of the facts of these notable floods with respect to the New England rivers, for permanent record and for study and reference by engineers concerned with the building of highways, bridges, and industrial plants, planners of river development, and others. Similar volumes for the region from the Hudson River to the Susquehanna River and for the Potomac, James, and upper Ohio River Basins are presented in companion Water-Supply Papers 799 and 800 respectively. In this volume records of stage and discharge for the period Including the floods are presented for about 150 measurement stations; peak discharges with comparative data for other floods at more than 400 measurement points are summarized; crest stages along an aggregate length of stream channel of 2,820 miles are tabulated; and results of detailed studies of the rainfall and run-off and many other kinds of flood information are presented.

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The floods of March 1936, Part 3, Potomac, James, and upper Ohio Rivers

During the period March 9-22, 1936, there occurred in close succession over the northeastern United States, from the James and upper Ohio River Basins in Virginia and Pennsylvania to the river basins of Maine, two extraordinarily heavy storms, in which the precipitation was almost entirely in the form of rain. The depths of rainfall mark this period as one of the greatest concentrations of precipitation, in respect to time and magnitude of the area covered, of which there is record in this country. At the time of the rain there were also accumulations of snow on the ground over much of the storm-affected region that were large for the season. The comparatively warm temperatures associated with the storms thawed the snow and added materially to the quantities of water to be disposed of by drainage into the waterways, by surface storage in lakes, ponds, and reservoirs, by absorption in the ground, and, probably in comparatively negligible degree, by evaporation. The total quantity of water that had to be disposed of in these ways ranged between 10 and 30 inches in depth over much of the region. The water disposed of by natural storage, absorption, and evaporation amounted to average depths over the many river basins generally within the range of 1 to 3 inches, with a significant degree of uniformity and systematic areal distribution. The remainder of the rain and snow water, generally much larger or even several times larger in amount than surface storage, absorption, and evaporation, required accommodation by the channels of the brooks, creeks, and rivers. There were generally two distinct flood peaks, and in many of the basins the destruction was seriously aggravated, especially during the first flood, by the break-up of thick ice cover accumulated through a winter of exceptionally continuous and severe cold weather. The resulting floods were extraordinarily severe, and records of river stages, extending on some streams back to or nearly to the time of settlement by white men, were broken many of them by wide margins. The peak of the Connecticut River at Hartford, Conn., was 8.6 feet higher than had been experienced since the settlement by white men, 300 years ago. The Susquehanna River at Harrisburg, Pa., was 3.5 feet higher than had been known in a period of record covering about 200 years. The Ohio River at Pittsburgh, Pa., was 6.1 feet higher than had been known in the period beginning 1762. This volume presents many of the facts of these notable floods with respect to the New England rivers, for permanent record and for study and reference by engineers concerned with the building of highways, bridges, and industrial plants, planners of river development, and others. Similar volumes for the region from the Hudson River to the Susquehanna River and for the Potomac, James, and upper Ohio River Basins are presented in companion Water-Supply Papers 799 and 800 respectively. In this volume records of stage and discharge for the period Including the floods are presented for about 150 measurement stations; peak discharges with comparative data for other floods at more than 400 measurement points are summarized; crest stages along an aggregate length of stream channel of 2,820 miles are tabulated; and results of detailed studies of the rainfall and run-off and many other kinds of flood information are presented.

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