Search USGS⌕ Search

SEARCH · Search USGS

Results for “Land and Reservoir Management”

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

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

At least 91 records · Page 5Linked to original sources
USGS2023

Leveraging multimission satellite data for spatiotemporally coherent cyanoHAB monitoring

Cyanobacteria harmful algal blooms (cyanoHABs) present a critical public health challenge for aquatic resource and public health managers. Satellite remote sensing is well-positioned to aid in the identification and mapping of cyanoHABs and their dynamics, giving freshwater resource managers a tool for both rapid and long-term protection of public health. Monitoring cyanoHABs in lakes and reservoirs with remote sensing requires robust processing techniques for generating accurate and consistent products across local and global scales at high revisit rates. We leveraged the high spatial and temporal resolution chlorophyll-a (Chl a ) and phycocyanin (PC) maps from two multispectral satellite sensors, the Sentinel-2 (S2) MultiSpectral Instrument (MSI) and the Sentinel-3 (S3) Ocean Land Colour Instrument (OLCI) respectively, to study bloom dynamics in Utah Lake, United States, for 2018. We used established Mixture Density Networks (MDNs) to map Chl a from MSI and train new MDNs for PC retrieval from OLCI, using the same architecture and training dataset previously proven for PC retrieval from hyperspectral imagery. Our assessment suggests lower median uncertainties and biases (i.e., 42% and -4%, respectively) than that of existing top-performing PC algorithms. Additionally, we compared bloom trends in MDN-based PC and Chl a products to those from a satellite-derived cyanobacteria cell density estimator, the cyanobacteria index (CI-cyano), to evaluate their utility in the context of public health risk management. Our comprehensive analyses indicate increased spatiotemporal coherence of bloom magnitude, frequency, occurrence, and extent of MDN-based maps compared to CI-cyano and potential for use in cyanoHAB monitoring for public health and aquatic resource managers.

Utah↗
USGS2019

Measurement of cyanobacteria bloom magnitude using satellite remote sensing

Cyanobacterial harmful algal blooms (cyanoHABs) are a serious environmental, water quality and public health issue worldwide because of their ability to form dense biomass and produce toxins. Models and algorithms have been developed to detect and quantify cyanoHABs biomass using remotely sensed data but not for quantifying bloom magnitude, information that would guide water quality management decisions. We propose a method to quantify seasonal and annual cyanoHAB magnitude in lakes and reservoirs. The magnitude is the spatio-temporal mean of weekly or biweekly maximum cyanobacteria biomass for the season or year. CyanoHAB biomass is quantified using a standard reflectance spectral shape-based algorithm that uses data from Medium Resolution Imaging Spectrometer (MERIS). We demonstrate the method to quantify annual and seasonal cyanoHAB magnitude in Florida and Ohio respectively during 2003-2011 and rank the lakes based on median magnitude over the study period. The new method can be applied to Ocean Land Color Imager (OLCI) on Sentinel-3 data for assessment of cyanoHABs and the change over time, even with issues such as variable data acquisition frequency or sensor calibration uncertainties between satellites. CyanoHAB magnitude can support monitoring and management decision-making for recreational and drinking water sources.

Florida, Ohio↗
USGS2016

Climate, invasive species and land use drive population dynamics of a cold-water specialist

Climate change is an additional stressor in a complex suite of threats facing freshwater biodiversity, particularly for cold-water fishes. Research addressing the consequences of climate change on cold-water fish has generally focused on temperature limits defining spatial distributions, largely ignoring how climatic variation influences population dynamics in the context of other existing stressors. We used long-term data from 92 populations of bull trout Salvelinus confluentus – one of North America's most cold-adapted fishes – to quantify additive and interactive effects of climate, invasive species and land use on population dynamics (abundance, variability and growth rate). Populations were generally depressed, more variable and declining where spawning and rearing stream habitat was limited, invasive species and land use were prevalent and stream temperatures were highest. Increasing stream temperature acted additively and independently, whereas land use and invasive species had additive and interactive effects (i.e. the impact of one stressor depended on exposure to the other stressor). Most (58%–78%) of the explained variation in population dynamics was attributed to the presence of invasive species, differences in life history and management actions in foraging habitats in rivers, lakes and reservoirs. Although invasive fishes had strong negative effects on populations in foraging habitats, proactive control programmes appeared to effectively temper their negative impact. Synthesis and applications . Long-term demographic data emphasize that climate warming will exacerbate imperilment of cold-water specialists like bull trout, yet other stressors – especially invasive fishes – are immediate threats that can be addressed by proactive management actions. Therefore, climate-adaptation strategies for freshwater biodiversity should consider existing abiotic and biotic stressors, some of which provide potential and realized opportunity for conservation of freshwater biodiversity in a warming world.

Journal of Applied Ecology↗
USGS2019

Toward explaining nitrogen and phosphorus trends in Chesapeake Bay tributaries, 1992-2012

Understanding trends in stream chemistry is critical to watershed management, and often complicated by multiple contaminant sources and landscape conditions changing over varying time scales. We adapted spatially-referenced regression (SPARROW) to infer causes of recent nutrient trends in Chesapeake Bay tributaries by relating observed fluxes during 1992, 2002, and 2012 to contemporary inputs and watershed conditions. The annual flow-normalized nitrogen flux to the bay from its watershed declined by 14 percent to 127,000 Mg (metric tons) between 1992 and 2012, due primarily (more than 80 percent of the decline) to reduced point sources. The remainder of the decline was due to reduced atmospheric deposition (13 percent) and urban non-point sources. Agricultural inputs, which contribute most nitrogen to the bay, changed little, although trends in the average nitrogen yield (flux per unit area) from cropland and pasture to streams in some settings suggest possible effects of evolving nutrient applications or other land management practices. Point sources of phosphorus to local streams declined by half between 1992 and 2012, while non-point inputs were relatively unchanged. Annual phosphorus delivery to the bay increased by 9 percent to 9,570 Mg between 1992 and 2012, however, due mainly to reduced retention in the Susquehanna River at Conowingo Reservoir.

Delaware, Maryland, New Jersey, Pennsylvania, Virg↗
USGS2004

Reconnaissance of chemical and biological quality in the Owyhee River from the Oregon State line to the Owyhee Reservoir, Oregon, 2001–02

The Owyhee River drains an extremely rugged and sparsely populated landscape in northern Nevada, southwestern Idaho, and eastern Oregon. Most of the segment between the Oregon State line and Lake Owyhee is part of the National Wild and Scenic Rivers System, and few water-quality data exist for evaluating environmental impacts. As a result, the U.S. Geological Survey, in cooperation with the Bureau of Land Management, assessed this river segment to characterize chemical and biological quality of the river, identify where designated beneficial uses are met and where changes in stream quality occur, and provide data needed to address activities related to environmental impact assessments and Total Maximum Daily Loads. Water-quality issues identified at one or more sites were water temperature, suspended sediment, dissolved oxygen, pH, nutrients, trace elements, fecal bacteria, benthic invertebrate communities, and periphyton communities. Generally, summer water temperatures routinely exceeded Oregon's maximum 7-day average criteria of 17.8 degrees Celsius. The presence of few coldwater taxa in benthic invertebrate communities supports this observation. Suspended-sediment concentrations during summer base flow were less than 10 milligrams per liter (mg/L). Dissolved solids concentrations ranged from 46 to 222 mg/L, were highest during base flow, and tended to increase in a downstream direction. Chemical compositions of water samples indicated that large proportions of upland-derived water extend to the lower reaches of the study area during spring runoff. Dissolved fluoride and arsenic concentrations were highest during base flow and may be a result of geothermal springs discharging to the river. No dissolved selenium was detected. Upstream from the Rome area, spring runoff concentrations of suspended sediment ranged from 0 to 52 mg/L, and all except at the Three Forks site were typically below 20 mg/L. Stream-bottom materials from the North Fork Owyhee River, an area with no mines, were enriched with nine trace elements, which indicates that this basin may be a natural source of these elements. Near Rome, the part of the study area not included in the National Wild and Scenic Rivers System, land-use impacts resulted in elevated populations of Escherichia coli bacteria ( E. coli ) during base flow and elevated concentrations of nitrogen and phosphorus during spring runoff. Sites in this area had the highest numbers of benthic invertebrates; the fewest Ephemeroptera, Plecoptera, and Trichoptera taxa; and the highest Hilsenhoff Biotic Index scores. These results suggest degraded stream quality. Periphyton communities at sites in this area approached nuisance levels and could cause significant dissolved oxygen depletions and pH values that exceed Oregon's recommended criteria. Stream-bottom materials from Jordan Creek were enriched with mercury and manganese, which probably were ultimately caused by past mining in that basin. Below Crooked Creek, elevated suspended sediment concentrations (142 mg/L), phosphorus concentrations (0.23 mg/L), and E. coli populations (370 most probable number per 100 milliliters) during the largest spring runoff event could be the result of inputs at the lower end of Jordan Valley and (or) inputs from Crooked Creek. The New Zealand Mud Snail, a highly competitive gastropod introduced to the Snake River in the 1980s, was collected just downstream from the Crooked Creek confluence.

Idaho;Nevada;Oregon↗
USGS2015

Natural soil reservoirs for human pathogenic and fecal indicator bacteria

Soils receive inputs of human pathogenic and indicator bacteria through land application of animal manures or sewage sludge, and inputs by wildlife. Soil is an extremely heterogeneous substrate and contains meso- and macrofauna that may be reservoirs for bacteria of human health concern. The ability to detect and quantify bacteria of human health concern is important in risk assessments and in evaluating the efficacy of agricultural soil management practices that are protective of crop quality and protective of adjacent water resources. The present chapter describes the distribution of selected Gram-positive and Gram-negative bacteria in soils. Methods for detecting and quantifying soilborne bacteria including extraction, enrichment using immunomagnetic capture, culturing, molecular detection and deep sequencing of metagenomic DNA to detect pathogens are overviewed. Methods for strain phenotypic and genotypic characterization are presented, as well as how comparison with clinical isolates can inform the potential for human health risk.

Book chapter↗
USGS1970

Sediment yields of Wisconsin streams

Sediment in Wisconsin streams causes economic and engineering problems in water management and reduces the value of water for nearly all uses. Sediment produces problems such as reduced reservoir capacity, navigation hazards, increased cost of water treatment, property damage, temporary loss of farmland, destruction of feeding and nesting grounds of fish, and destruction of wildlife habitat. Sediment in water also reduces the aesthetic value of surface waters and is detrimental to the State's tourist and recreation industry. The yield of sediment from a drainage basin is subject to many environmental influences. Most sediment results from the weathering and erosion of soil and rock materials. Other factors such as rainfall intensity, runoff rate, topography, rock type, soil characteristics, vegetal cover, and land use also influence the rate of sediment production and movement. An understanding of the many parameters that influence sediment yield is a basic need for managing the State's water resources. The purpose of this report is to describe the magnitude and variability of sediment in Wisconsin streams, to relate sediment yields to the local environment, and to identify areas that need further study. The report is based on sediment data from 44 stream-gaging sites throughout the State. Determination of local areas of erosion and deposition are beyond the scope of the report.

Wisconsin↗
USGS1960

Water management, agriculture, and ground-water supplies

Encyclopedic data on world geography strikingly illustrate the drastic inequity in the distribution of the world's water supply. About 97 percent of the total volume of water is in the world's oceans. The area of continents and islands not under icecaps, glaciers, lakes, and inland seas is about 57.5 million square miles, of which 18 million (36 percent) is arid to semiarid. The total world supply of water is about 326.5 million cubic miles, of which about 317 million is in the oceans and about 9.4 million is in the land areas. Atmospheric moisture is equivalent to only about 3,100 cubic miles of water. The available and accessible supply of ground water in the United States is somewhat more than 53,000 cubic miles (about 180 billion acre ft). The amount of fresh water on the land areas of the world at any one time is roughly 30,300 cubic miles and more than a fourth of this is in large fresh-water lakes on the North American Continent. Annual recharge of ground water in the United States may average somewhat more than 1 billion acre-feet yearly, but the total volume of ground water in storage is equivalent to all the recharge in about the last 160 years. This accumulation of ground water is the nation's only reserve water resource, but already it is being withdrawn or mined on a large scale in a few areas. The principal withdrawals of water in the United States are for agriculture and industry. Only 7.4 percent of agricultural land is irrigated, however; so natural soil moisture is the principal source of agricultural water, and on that basis agriculture is incomparably the largest water user. In view of current forecasts of population and industrial expansion, new commitments of water for agriculture should be scrutinized very closely, and thorough justification should be required. The 17 Western States no longer contain all the large irrigation developments. Nearly 10 percent of the irrigated area is in States east of the western bloc, chiefly in several Southeastern States. Ground water is not completely 'self-renewing' because, where it is being mined, the reserve is being diminished and the reserve would be renewed only if pumping were stopped. Water is being mined at the rate of 5 million acre-feet per year in Arizona and 6 million in the High Plains of Texas. In contrast, water has been going into storage in the Snake River Plain of Idaho, where deep percolation from surface-water irrigation has added about 10 million acre-feet of storage since irrigation began. Situations in California illustrate problems of land subsidence resulting from pumping and use of water, and deterioration of ground-water reservoirs due to sea-water invasion. Much water development in the United States has been haphazard and rarely has there been integrated development of ground water and surface water. Competition is sharpening and new codes of water law are in the making. New laws, however, will not prevent the consequences of bad management. An important task for water management is to recognize the contingencies that may arise in the future and to prepare for them. The three most important tasks at hand are to make more efficient use of water, to develop improved quantitative evaluations of water supplies arid their quality, and to develop management practices which are based on scientific hydrology.

Circular↗
USGS2006

Effects of roads and well pads on erosion in the Largo Canyon watershed, New Mexico, 2001-02

Largo Canyon, located in the San Juan Basin of northwestern New Mexico, is one of the longest dry washes in the world. Oil and gas production in the San Juan Basin, which began in the 1940's, required the development of an extensive network of dirt roads to service the oil and gas wells in the Navajo Reservoir area. Presently, there are about eight wells per square mile, and the density of oil and gas wells is expected to increase. Potential environmental effects on landscape stability that may result from the additional roads and well pads have not been documented. In 2001, the U.S. Geological Survey began a study in cooperation with the Bureau of Land Management to evaluate the effects of roads and well pads associated with oil and gas operations on the erosion potential of Bureau of Land Management lands in the Largo Canyon watershed. The effects of roads and well pads on erosion were quantified by installing sediment dams (dams) and by surveying transects across roads and well pads. Data from 26 dams were used in the analysis. Dams were installed at 43 sites: 21 on hillsides upslope from roads or pads to measure erosion from hillslopes, 11 at the downslope edges of roads to measure erosion from roads, and 11 at the downslope edges of well pads to measure erosion from well pads. Pairs of survey transects were established at nine well pads and two road locations. Sediment-accumulation data for 26 dams, recorded at 17 measurement intervals, indicate that average erosion rates at the dams significantly correlate to size of the contributing area. The average erosion rate normalized by drainage area was 0.001 foot per year below roads, 0.003 foot per year on hillslopes, and 0.011 foot per year below well pads. Results of a two-sample t-test indicate that there was no significant difference in average erosion rates for dams located on hillslopes and below roads, whereas average erosion rates were significantly greater for dams below well pads than for dams on hillslopes and dams below roads. The average erosion rates estimated from the data collected during this study most likely represent minimum erosion rates. Sediment-accumulation data for measurement intervals and for dams that were breached during 2002, resulting from the large volume of runoff generated by high-intensity storms, were not used to compute erosion rates. For this reason, the higher range of erosion rates is underrepresented and the results of this study are biased toward the lower end of the range of erosion rates. Measurements along road transects generally indicate that sediment is eroded from the top of road berms and redeposited at the base of the berms and may be transported downslope along the road. Measurements along well-pad transects generally indicate that sediment eroded from hillslopes is transported over the surface of the well pad and down the well-pad edges. Based on field observations, roads aligned parallel to topographic contours facilitate erosional processes in two ways: (1) roads cut across and collect runoff from previously established drainages and (2) roads, where they are cut into hillsides or into the land surface, provide focal points for the initiation of erosion. Roads aligned across topographic contours can serve as conduits to channel runoff but do not constitute a large percentage of the road network.

Scientific Investigations Report↗
USGS2022

The gap between experts, farmers and non-farmers on perceived environmental vulnerability and the influence of values and beliefs

Science has played a mixed role in guiding conservation and sustainability-oriented decision-making by individuals, policymakers, institutions, and governments. Not all science-based conservation and sustainability initiatives that address issues facing humanity and ecosystems and global problems have gained public support. Conservation decisions and policy prescriptions are and may be based on perceptions about and experiences with the environment, local land use, and ecosystems that may not align with or be grounded in science or evidence from experts in the field. Values, beliefs, and perceptions associated with nature play a critical role in how individuals view biodiversity conservation, sustainability, and natural resource management . This study first examines the gap between experts (scientists and other field experts) and the public (farmers and non-farmers) about the state of water and land resources, wildlife and associated habitats, and aquatic biodiversity in the Smoky Hill River Watershed in western Kansas. Second, the study examines the role that values and beliefs play in shaping environmental perceptions for farmers and non-farmers. Analysis confirms that a gap between experts and farmers/non-farmers does exist, especially with respect to the state of the Ogallala Aquifer, playas, rivers and streams, lakes and reservoirs, native grasslands, wildlife habitats, farmland, native fish populations, and wildlife species. Ordered-logistic regression analyses, meanwhile, indicate that farmer and non-farmer perceptions about the state of the local environment are influenced by traditional and self-interested values, as well as environmental values and beliefs, but less so by religiosity and political ideology. Despite broad takeaways, results exhibited heterogeneity across the farmer and non-farmer subpopulations. If environmental professionals cannot align ecological data, stakeholders’ values/perceptions, and policies, then the existing body of technical research and management on sustainability in natural and social sciences may be of little value.

Journal of Environmental Management↗
USGS2007

Eutrophication study at the Panjiakou-Daheiting Reservoir system, northern Hebei Province, People's Republic of China: Chlorophyll-a model and sources of phosphorus and nitrogen

Concentrations, loads, and sources of nitrate and total phosphorus were investigated at the Panjiakou and Daheiting Reservoir system in northern Hebei Province, People's Republic of China. The Luan He River is the primary source of water to these reservoirs, and the upstream watershed has a mix of land uses including agriculture, forest, and one large urban center. The reservoirs have a primary use for storage of drinking water and partially supply Tianjin City with its annual needs. Secondary uses include flood control and aqua culture (fish cages). The response of the reservoir system from phosphorus input, with respect to chlorophyll- a production from algae, was fitted to a model of normalized phosphorus loading that regresses the average summer-time chlorophyll- a concentration to the average annual phosphorus concentration of the reservoir. Comparison of the normalized phosphorus loading and chlorophyll- a response of this system to other reservoirs throughout the world indicate a level of eutrophication that will require up to an approximate 5–10-fold decrease in annual phosphorus load to bring the system to a more acceptable level of algal productivity. Isotopes of nitrogen and oxygen in dissolved nitrate were measured from the headwater streams and at various locations along the major rivers that provide the majority of water to these reservoirs. Those isotopic measurements indicate that the sources of nitrate change from natural background in the rivers to animal manure and septic waste upstream of the reservoir. Although the isotopic measurements suggest that animal and septic wastes are a primary source of nutrients, measurements of the molar ratio of nitrogen to phosphorus are more indicative of row-cropping practices. Options for reduction of nutrient loads include changing the management practices of the aqua culture, installation of new sewage treatment systems in the large urbanized area of the upper watershed, and agricultural management practices that would reduce the loading of nutrients and soil erosion from that land use.

Agricultural Water Management↗
USGS2019

Integrated hydrologic modeling of the Salinas River, California, for sustainable water management

The Salinas River is the largest river in California’s Central Coast region. Groundwater resources of the Salinas River basin are used to meet water supply needs, including crop irrigation and municipal water supply. Two large multipurpose reservoirs also supply irrigation and municipal water uses. Historical imbalances between supply and demand have resulted in sinking groundwater levels, seawater intrusion, regulatory actions on pumping, adjudication, and requirements for minimum in-stream fish flows. Present needs include finding replacement water supplies and improving watershed management to comply with legal mandates, adapt to future climate variability and landuse conversions, and improve environmental conditions. The Salinas Valley Integrated Hydrologic Model (SVIHM) was developed to help water managers evaluate and adjust to projected impacts on water supplies and demands in the Salinas Valley watershed caused by changes in land use, population, and climate. The SVIHM includes four modeling components: (1) the Basin Characterization Model (BCM), (2) the Hydrologic Simulation Program – FORTRAN (HSPF), (3) MODFLOW - One Water Hydrologic Model (MF-OWHM), and (4) the Surface Water Operations (SWO) package. The BCM and HSPF components compose the Salinas Valley Watershed Model (SVWM). The 4,530 square-mile (mi2) SVWM domain encompasses the entire Salinas River watershed, as well as coastal drainages adjacent to the Salinas River outflow, and includes two separate and connected HSPF model domains, the 2,540 mi2 upper Salinas River and the 1,990 mi2 lower Salinas River models. SVWM (1) simulates the water budget for the entire Salinas River basin containing both the SVIHM domain as well as the mountainous terrain of the tributary headwater areas not included in the SVIHM; and (2) was used to develop the 148 boundary inflows for the SVIHM. Simulated evapotranspiration (ET) is the largest component of the water budget after precipitation, with a 71-year average basin-wide ET of 13.9 in/yr, compared to the basin-wide average precipitation of 18.4 in/yr. Simulated ET ranges from 15 to 29 in/yr along the western side of the SVWM to less than 10 in/yr throughout the valley floor and in the southeast part of the Salinas River watershed. The simulated total 71-year average inflow to the SVIHM was 890 ft3/sec (about 640,000 acre-feet per year), with the highest average inflow of 270 ft3/sec simulated for the Nacimiento River; whereas, the simulated 71-year average streamflow at the mouth of the Salinas River was only about 190 ft3/sec, indicating that most of the streamflow generated in the Salinas River basin is lost to channel seepage. The lack of sustained baseflow causes streamflow to be highly sensitive to the temporal variability in precipitation, especially during the drier periods, and this increases the importance of developing adequate reservoir management, flow augmentation, and conjunctive water use scenarios for potential future drought periods and potentially increased temporal variability in precipitation.

California↗
USGS2004

Water Resources Data for Oregon, Water Year 2003

The annual Oregon hydrologic data report is one of a series of annual reports that document hydrologic data gathered from the U.S. Geological Survey's surface- and ground-water data-collection networks in each State, Puerto Rico, and the Trust Territories. These records of streamflow, ground-water levels, and quality of water provide the hydrologic information needed by State, local and Federal agencies, and the private sector for developing and managing our Nation's land and water resources. This report includes records on both surface and ground water in Oregon and contains discharge records for 199 stream-gaging stations, 25 partial-record or miscellaneous streamflow stations, and 8 crest-stage partial-record streamflow stations; stage-only records for 6 gaging stations; stage and content records for 26 lakes and reservoirs; and water-quality records collected at 127 streamflow-gaging stations, 2 atmospheric deposition stations, and 11 ground-water sites.

Water Data Report↗
USGS2005

Water resources data for Oregon, water year 2004

The annual Oregon water data report is one of a series of annual reports that document hydrologic data gathered from the U.S. Geological Survey's surface- and ground-water data-collection networks in each State, Puerto Rico, and the Trust Territories. These records of streamflow, ground-water levels, and quality of water provide the hydrologic information needed by State, local, Tribal, and Federal agencies and the private sector for developing and managing our Nation's land and water resources. This report contains water year 2004 data for both surface and ground water, including discharge records for 209 streamflow-gaging stations, 42 partial-record or miscellaneous streamflow stations, and 9 crest-stage partial-record streamflow stations; stage-only records for 6 gaging stations; stage and content records for 15 lakes and reservoirs; water-level records from 12 long-term observation wells; and water-quality records collected at 133 streamflow-gaging stations and 1 atmospheric deposition station.

Water Data Report↗
USGS2003

Water Resources Data for Oregon, Water Year 2002

The annual Oregon hydrologic data report is one of a series of annual reports that document hydrologic data gathered from the U.S. Geological Survey's surface- and ground-water data-collection networks in each State, Puerto Rico, and the Trust Territories. These records of streamflow, ground-water levels, and quality of water provide the hydrologic information needed by State, local and Federal agencies, and the private sector for developing and managing our Nation's land and water resources. This report includes records on both surface and ground water in the State and contains discharge records for 181 stream-gaging stations, 47 partial-record or miscellaneous streamflow stations, and 8 crest-stage partial-record streamflow stations; stage-only records for 6 gaging stations; stage and content records for 26 lakes and reservoirs; and water-quality records for 127 streamflow-gaging stations, 2 atmospheric deposition stations, and 11 ground-water sites.

Water Data Report↗
USGS2017

Dam removal: Listening in

Dam removal is widely used as an approach for river restoration in the United States. The increase in dam removals—particularly large dams—and associated dam-removal studies over the last few decades motivated a working group at the USGS John Wesley Powell Center for Analysis and Synthesis to review and synthesize available studies of dam removals and their findings. Based on dam removals thus far, some general conclusions have emerged: (1) physical responses are typically fast, with the rate of sediment erosion largely dependent on sediment characteristics and dam-removal strategy; (2) ecological responses to dam removal differ among the affected upstream, downstream, and reservoir reaches; (3) dam removal tends to quickly reestablish connectivity, restoring the movement of material and organisms between upstream and downstream river reaches; (4) geographic context, river history, and land use significantly influence river restoration trajectories and recovery potential because they control broader physical and ecological processes and conditions; and (5) quantitative modeling capability is improving, particularly for physical and broad-scale ecological effects, and gives managers information needed to understand and predict long-term effects of dam removal on riverine ecosystems. Although these studies collectively enhance our understanding of how riverine ecosystems respond to dam removal, knowledge gaps remain because most studies have been short (< 5 years) and do not adequately represent the diversity of dam types, watershed conditions, and dam-removal methods in the U.S.

Water Resources Research↗
USGS2022

Integrative monitoring strategy for marine and freshwater harmful algal blooms and toxins across the freshwater-to-marine continuum

Many coastal states throughout the USA have observed negative effects in marine and estuarine environments caused by cyanotoxins produced in inland waterbodies that were transported downstream or produced in the estuaries. Estuaries and other downstream receiving waters now face the dual risk of impacts from harmful algal blooms (HABs) that occur in the coastal ocean as well as those originating in inland watersheds. Despite this risk, most HAB monitoring efforts do not account for hydrological connections in their monitoring strategies and designs. Monitoring efforts in California have revealed the persistent detection of cyanotoxins across the freshwater-to-marine continuum. These studies underscore the importance of inland waters as conduits for the transfer of cyanotoxins to the marine environment and highlight the importance of approaches that can monitor across hydrologically connected waterbodies. A HAB monitoring strategy is presented for the freshwater-to-marine continuum to inform HAB management and mitigation efforts and address the physical and hydrologic challenges encountered when monitoring in these systems. Three main recommendations are presented based on published studies, new datasets, and existing monitoring programs. First, HAB monitoring would benefit from coordinated and cohesive efforts across hydrologically interconnected waterbodies and across organizational and political boundaries and jurisdictions. Second, a combination of sampling modalities would provide the most effective monitoring for HAB toxin dynamics and transport across hydrologically connected waterbodies, from headwater sources to downstream receiving waterbodies. Third, routine monitoring is needed for toxin mixtures at the land–sea interface including algal toxins of marine origins as well as cyanotoxins that are sourced from inland freshwater or produced in estuaries. Case studies from California are presented to illustrate the implementation of these recommendations, but these recommendations can also be applied to inland states or regions where the downstream receiving waterbody is a freshwater lake, reservoir, or river.

California, Oregon↗
USGS2012

Availability and distribution of low flow in Anahola Stream, Kauaʻi, Hawaiʻi

Anahola Stream is a perennial stream in northeast Kauaʻi, Hawaiʻi, that supports agricultural, domestic, and cultural uses within its drainage basin. Beginning in the late 19th century, Anahola streamflow was diverted by Makee Sugar Company at altitudes of 840 feet (upper intake) and 280 feet (lower intake) for irrigating sugarcane in the Keālia area. When sugarcane cultivation in the Keālia area ceased in 1988, part of the Makee Sugar Company’s surface-water collection system (Makee diversion system) in the Anahola drainage basin was abandoned. In an effort to better manage available surface-water resources, the State of Hawaiʻi Department of Hawaiian Home Lands is considering using the existing ditches in the Anahola Stream drainage basin to provide irrigation water for Native Hawaiian farmers in the area. To provide information needed for successful management of the surface-water resources, the U.S. Geological Survey investigated the availability and distribution of natural low flow in Anahola Stream and also collected low-flow data in Goldfish Stream, a stream that discharges into Kaneha Reservoir, which served as a major collection point for the Makee diversion system. Biological surveys of Anahola Stream were conducted as part of a study to determine the distribution of native and nonnative aquatic stream fauna. Results of the biological surveys indicated the presence of the following native aquatic species in Anahola Stream: ʻoʻopu ʻakupa (Sandwich Island sleeper) and ʻoʻopu naniha (Tear-drop goby) in the lower stream reaches surveyed; and ʻoʻopu nākea (Pacific river goby), ʻoʻopu nōpili (Stimpson’s goby), and ʻōpae kalaʻole (Mountain shrimp) in the middle and upper stream reaches surveyed. Nonnative aquatic species were found in all of the surveyed stream reaches along Anahola Stream. The availability and distribution of natural low flow were determined using a combination of discharge measurements made from February 2011 to May 2012 at low-flow partial-record and seepage-run stations established at locations of interest along study-area streams. Upstream of the upper intake, the estimated natural (undiverted) median flow in Anahola Stream is 2.7 million gallons per day, and the flow is expected to be greater than or equal to 0.97 million gallons per day 95 percent of the time. About 0.7 mile upstream of the lower intake and downstream from the confluence with Keaʻoʻopu Stream, the estimated natural (undiverted) median flow in Anahola Stream is 6.3 million gallons per day, and the flow is expected to be greater than or equal to 2.7 million gallons per day 95 percent of the time. In Goldfish Stream, about 0.4 mile upstream from the point of discharge into Kaneha Reservoir, the estimated natural median flow is 0.54 million gallons per day, and the flow is expected to be greater than or equal to 0.23 million gallons per day 95 percent of the time. The discharge estimates are representative of low-flow conditions in the study-area streams, and they are applicable to the base period (water years 1961–2011) over which they have been computed. The distribution of natural low flow in Anahola Stream was characterized through data collected during wet- and dry-season seepage runs. Seepage-run results show that Anahola Stream was generally a gaining stream under natural low-flow conditions. During the wet-season seepage run, Anahola Stream at the station located upstream of tributary Kaʻalula Stream had more than five times the flow that was measured upstream from the upper intake. The estimated total gain (including tributary inflow) in the 6.1-mile seepage-run reach was 6.97 million gallons per day; about 42 percent of that gain was groundwater discharge to the main channel of Anahola Stream. During the dry-season seepage run, about 34 percent of the estimated total gain of 3.93 million gallons per day in the same seepage-run reach was groundwater discharge to the main channel of Anahola Stream. A 15-percent seepage loss was estimated in a 0.3-mile reach downstream from the confluence of Anahola and Keaʻoʻopu Streams. The report summarizes scenarios that describe (1) surface-water availability under regulated conditions of Anahola Stream if the upper and lower intakes are restored in the future; and (2) amount of flow available for agricultural use at the upper intake under a variety of potential instream-flow standards that may be established by the State of Hawaiʻi for the protection of instream uses.

Hawai'i↗