Search USGS⌕ Search

Geology topics

Research about New York

Source-linked reports with geographic coverage including New York.

At least 19 recordsLinked to original sources

Hydrogeology and water quality of the unconsolidated aquifer system in the lower Fall Creek valley, Tompkins County, New York

The U.S. Geological Survey, in cooperation with Tompkins County and the Town of Dryden, conducted a hydrogeologic investigation of the lower Fall Creek unconsolidated aquifer system in Tompkins County, New York. This study is part of an ongoing effort to characterize major valley-fill aquifers in the region to support sustainable groundwater management. The lower Fall Creek valley, encompassing the Village of Freeville, the unincorporated communities of Etna, and the hamlets of McLean and Varna, has experienced moderate development and relies heavily on groundwater for residential, agricultural, and commercial use. The study area spans approximately 51 square miles along the boundary of the Allegheny Plateau and North Rim of the Allegheny Plateau physiographic provinces. The aquifer system, composed primarily of glacially derived sand and gravel deposits, includes both unconfined and confined aquifer units. For the approximately 2,300 people who live over the aquifers, groundwater is the sole source of drinking water. In some areas, such as the Village of Freeville, artesian conditions exist, with potentiometric heads exceeding 25 feet above land surface. This report describes the hydrogeologic framework, aquifer distribution, groundwater-flow dynamics, and water quality of the lower Fall Creek aquifer system. Groundwater is generally hard and contains elevated concentrations of redox-sensitive constituents, such as iron and manganese relative to U.S. Environmental Protection Agency secondary maximum contaminant levels. Arsenic was not detected above the U.S. Environmental Protection Agency maximum contaminant level during this study but remains a regional concern due to past detections in the study area and nearby aquifers. The findings provide data for local planners and resource managers to use in understanding and protecting this water resource.

New York↗

Springs of the Catskill Mountains: A conduit flow system in predominantly siliciclastic strata

The Catskill Mountains of New York state are composed of thick sequences of interbedded mudstone, sandstone, and siltstone that are intercalated with thin beds of paludal limestone and calcareous mudstone. Sandstones often contain rip-up clasts of calcareous material at their bases and contain minor amounts of carbonate cement throughout their mass. This minor amount of calcareous material weathers out to produce thin zones of solutional porosity and permeability integrated within perched aquifers that feed perennial hillslope springs. Solutional features are evident within thin carbonate lenses and along fractures in sandstones, occasionally resulting in explorable cave-sized conduits. This study focuses on the behavior of bedrock springs and seeps in the headwaters of the Neversink River basin above the Neversink Reservoir. Bedrock springs are numerous throughout the Catskill Mountains and serve to provide baseflow to the headwater streams that tends to be more persistent during dry times than other baseflow sources. We observed dissolution-influenced conduits within the bedrock, and suffosional conduits within unconsolidated materials. Continuous water temperature at six springs was monitored at hourly intervals from May to October 2022 to investigate the thermal response of groundwater to daily and seasonal changes in air temperature along with event-based meteorological events. Temperature monitoring was augmented at some springs with time-lapse photography to evaluate persistence of flow. The thermal responses of springs to precipitation events were highly variable across sites, with some springs exhibiting flashy responses indicating a strong connection to the surface, while other springs showed muted or no thermal response to events. The seasonal thermal response also varied across sites having lag times of 23-48 days between peak air temperature and peak spring water temperature. The water temperatures and geochemical compositions of these bedrock springs support a conceptual model of multiple residence times, showing both event and seasonal groundwater storage within the conduit flow system that feeds the springs of the Catskill Mountains.

New York↗

Solar energy development selectively filters avian taxonomic and functional diversity across a perennial agricultural landscape

Solar energy is rapidly expanding across agricultural landscapes, yet its consequences for avian communities remain poorly understood, particularly among heterogeneous land-use matrices. In 2024 and 2025, we surveyed birds across 107 sites in New York State, including conventional solar arrays with mowing or sheep grazing to manage vegetation, solar-adjacent working lands (e.g. hayfields, pastures) and reference working lands independently located from solar arrays. We integrated diversity metrics across four trait dimensions—taxonomic, morphological, ecological and conservation status—and examined interactions between species-level abundance and traits to understand avian community responses to solar energy development. Avian species in solar sites tended to be common, non-migratory (in behaviour and wing morphology) and associated with shrubland or forest. Compared to reference working lands, bird communities in solar and solar-adjacent sites were less taxonomically diverse and were composed of fewer declining and range-restricted species. However, solar and solar-adjacent sites retained comparable diversity of intrinsic traits, suggesting that ecological function may persist despite apparent species filtering and functional reshuffling. While solar energy development can support avian communities with unique functional signatures, our findings suggest that conventional solar arrays sited on agricultural working lands in New York maintain low bird diversity and are unlikely to support conservation-priority species—such as grassland birds characterized by declining populations, migratory tendencies and open-habitat dependence. Synthesis and applications . Our study provides a pathway to leverage functional diversity to quantitatively characterize solar-associated avian communities and the ecological mechanisms that shape them. Our results suggest that meeting biodiversity conservation goals while achieving solar energy targets requires ecologically informed siting and processes, particularly across regions in which co-prioritization of conservation, agriculture and energy presents sustainability trade-offs.

New York↗

Predictability creates vulnerability: Long-term acoustic telemetry reveals hidden threat windows for endangered Atlantic sturgeon

1.Individual movement strategies govern access to important habitats but can expose certain animals to spatially and temporally variable threats, producing consistent, phenotype-specific differences in risk. For endangered Atlantic sturgeon ( Acipenser oxyrinchu s), migration timing shapes exposure risk to vessel strikes, dredging activity, and shifting estuarine conditions, yet management to minimize exposure to these threats is predominantly based on population-average patterns of river occupancy. 2. We analysed a decade of acoustic telemetry data from 195 Atlantic sturgeon in the Hudson River to quantify individual variation in migration timing. We clustered individuals into distinct behavioural phenotypes and evaluated the consistency of these phenotypes across years to determine whether certain individuals may be present in spatiotemporal areas that are not represented in current conservation frameworks. 3. Results identified two persistent phenotypes: the short-residency phenotype exhibiting synchronized occupancy typical of the prescribed Atlantic sturgeon spawning run and an extended-residency group that migrates into the river later, displays prolonged river occupancy and diffuse outmigration into the fall. Extended-residency individuals were last detected approximately 88 days after short-residency individuals and occupied habitats downriver of the presumed spawning grounds, extending the period of sturgeon presence into riverine habitats outside the current spatiotemporal area of conservation focus. 4. Individual phenotypic membership was repeatable across nearly a decade, indicating that these behaviours reflect stable, consistent phenotypes rather than stochastic variation. 5. Synthesis and applications . Our results reveal persistent intrapopulation movement diversity in the largest remaining Atlantic sturgeon population and highlight predictable periods during which a unique phenotype may experience disproportionate exposure to in-river threats. These findings indicate that environmental reviews, permitting decisions and seasonal work windows may benefit from incorporating phenotype-specific occupancy patterns and percentile-based estimates of river residency rather than relying solely on historical spawning dates or population averages. Expanding telemetry and monitoring designs to include broader spatial and seasonal sampling may further improve detection of overlooked movement strategies and reduce potential biases in demographic and habitat use assessments. More broadly, recognizing behavioural diversity in recovery planning may provide a more complete basis for evaluating habitat use, threat exposure, and conservation priorities across sturgeon populations.

New York↗

Barrier island geomorphic complexity drives storm and post-storm response

Barrier islands are at the forefront of climate-driven changes, with their resiliency threatened by rapid fluctuations in the physical drivers that shape them. Quantifying magnitudes and directions of storm-driven sediment fluxes and rates and modes of sediment recovery is essential for predicting barrier island trajectories. Yet scarce shoreface observations have limited such efforts. Here, shoreface-inclusive measurements of barrier sediment fluxes over five years following an extreme storm reveal distinct sediment redistribution patterns that vary with island geomorphology. Overwash fluxes were low compared with seaward fluxes, inlet-related landward transport, and previously modeled estimates. Without these observations, models may overestimate island elevation-building capacity that is key to sea-level adaptability. Post-storm recovery was incomplete despite human intervention, altering barrier sediment distribution from pre-storm conditions. This may increase vulnerability to future storms and rising water levels and suggests management approaches tailored to island geometry may better compete with climate change effects.

New York↗

Deep learning models for mapping surficial geology in selected physiographic regions of New York

Surficial geologic mapping is required for decisions including infrastructure and water-resource development and management. Deep learning, a type of machine learning that uses training data to self-learn and perform tasks, is explored as a tool to help increase efficiency of the labour- and time-intensive mapping process. Deep learning models were trained, and their potential to aid in mapping surficial geology was explored for two physiographic regions in New York: the high-relief Allegheny Plateau and the low-relief Erie-Ontario Lowlands. Key to the development of deep learning models is the availability of highly detailed surficial geologic maps in each of these regions from which the models can learn. Through exploring different groupings of surficial deposits and their corresponding spatial data, deep learning models were iteratively developed to reproduce published mapping for greater than 79% of the training areas, and with similar accuracy in test areas within the same physiographic region. These models were trained using only two inputs: high-resolution lidar data and previously published surficial geologic maps. This straightforward approach is intended to make the methods and models created easily reproducible using widely accessible datasets. This research describes the strengths and limitations of lidar-derived surficial geologic models and how broadly grouping surficial types, characteristics of different physiographic regions, and testing models in physiographic regions outside of their training areas affect model creation and performance. In addition, the models created could be used as a tool for mapping surficial geology in similar physiographic regions, in addition to establishing a framework for creating similar models elsewhere.

New York↗

Impacts of cross-shore winds, waves, and sand ridges on inner shelf circulation

Understanding of circulation on inner continental shelves needs to be advanced to accurately predict the transport and connection between the shelves and nearshore. The circulation over the storm-dominated Fire Island Shelf, New York and a series of in situ shoreface connected sand ridges was investigated through high-resolution field observations, numerical simulations of hydrodynamics, and principal component analyses. The along-shelf subtidal flows were more energetic than the cross-shelf subtidal flows. Alongshore winds were driving the along-shelf subtidal flow and the variability of water levels. The cross-shelf subtidal flows were dominantly onshore near the seabed and offshore near the surface: the processes significant in this two-layer exchange were cross-shore winds which were commonly overlooked in literature, alongshore winds through Coriolis, and bottom friction. The ridges were significant in changing the magnitude and even the direction of the pressure gradients and associated flows. Wave impacts including water level changes, Stokes drift, vortex force, and breaking became significant in the inner shelf and the nearshore during wave-energetic events. Depending on the directions of waves and winds, waves caused to accelerate or decelerate and even reverse the wind-induced flow. In case of more shore-normal waves, the cross-shore Stokes drift became more significant; its interaction with Earth's rotation and flow vorticity generated significant Stokes-Coriolis impacts and vortex force, respectively, in the alongshore. With results applicable to other shelf settings, this study advanced the understanding of spatial and temporal variations of flows along and across inner shelves under varying forcing conditions.

New York↗

Temporal replication and sampling efficiency in high-frequency autonomous and manual eDNA sampling

Environmental DNA (eDNA) sampling is a valuable tool for ecological research, but its reliability as a quantitative approach can be improved by accounting for unexplained spatiotemporal variability and autocorrelation in eDNA concentrations. Sampling designs with temporal replication can separate sampling variation from temporal variation, but obtaining true temporal replicates is difficult when samples are collected sequentially. Autosamplers may facilitate high-frequency eDNA sampling, but their sequential sampling structure raises questions about when closely spaced samples can reasonably be treated as temporal replicates. This 19.5-day study evaluated temporal variation in invasive Round Goby ( Neogobius melanostomus ) eDNA concentration at a single large-river site with short-term hydrologic variability. We used two synchronized autosamplers and a backpack sampler to collect samples as frequently as every 15 min using polyethersulfone (PES) or mixed cellulose ester (MCE) filters. We fit hierarchical temporal models that decomposed sampling and temporal variation, evaluated evidence for residual temporal correlation under alternative priors for the effective range, and used simulation to assess bias when closely spaced sequential samples were treated as simultaneous temporal replicates. We found evidence of residual temporal correlation at short lag scales, but the effective range of temporal correlation was weakly identified and sensitive to prior assumptions. Hydrologic covariates had limited explanatory support once temporal structure was accounted for. Simulations showed that treating sequential samples collected over 15–60 min windows as simultaneous temporal replicates can bias estimates of sampling and temporal variation, especially when temporal correlation is relatively weak. MCE filters produced higher expected recovered copy numbers than PES filters, while evidence for systematic differences among sampler types was weaker. These results emphasize that eDNA temporal replication should be collected as close together in time as possible, and that uncertainty in temporal correlation should be explicitly considered when designing and analyzing high-frequency eDNA surveys.

New York↗

3D Elevation Program—New York

Using 3D Elevation Program data, a modern illustration of each State's landscape showcases its elevation differences in vivid detail. Each State has been consistently adjusted and colorized according to its highest and lowest elevations, accentuating differences even in States with low relief. To further emphasize landforms, shaded relief has been added on top of the elevation colors.

New York↗

Modeling legacy nitrogen transport under instantaneous, steady-state, and transient groundwater flow conditions

In hydrologic settings where groundwater discharge contributes substantially to surface waters, legacy nitrogen in groundwater can confound surface water nitrogen loads estimated exclusively from current terrestrial sources. Additionally, legacy nitrogen in groundwater can contribute to lagged responses to nitrogen management efforts. Some methods of estimating groundwater contributions to surface water nitrogen loads account for legacy nitrogen, while others do not. The resulting differences are rarely quantified. We used a numerical modeling framework to compare three methods of estimating time-varying annual groundwater nitrogen loads to surface water receptors on eastern Long Island, New York. The instantaneous load method used steady-state contributing areas and includes no temporal groundwater lag. The second method used numerical simulations of nitrogen loads under steady-state flow, which captures groundwater transport lags but omits the annual variability in transient hydrologic stresses. The third method numerically simulated both transient groundwater flow and nitrogen transport to explicitly capture the effects of legacy nitrogen in groundwater. Depending on antecedent nitrogen and hydrologic conditions, historical nitrogen loads estimated from the numerical simulations were sometimes similar (<10% difference) and other times substantially different (±100%) from the instantaneous load estimates. Additionally, simulated future surface water nitrogen loads responded asymptotically over several decades following reductions in terrestrial nitrogen sources, further highlighting the effect of groundwater transport lag times. The comparison of the three methods, quantification of historical interannual variability, and prediction of lagged responses to nitrogen source reductions provide important context for decision makers using estimated groundwater nitrogen loads to help evaluate nitrogen management efficacy.

New York↗

U.S. Geological Survey Monitoring Milestones—Oe-151 at Woodgate, NY (433112075091501)

On July 9, 1926, monitoring well Oe-151 at Woodgate, New York (USGS ID 433112075091501) recorded its first groundwater data. Since then, the well has provided water data nearly continuously and has now reached a 100-year milestone for data collection. The well is part of the U.S. Geological Survey (USGS) Climate Response Network (CRN), which is a national network of wells selected to monitor natural groundwater conditions. Well Oe-151 is the first well in the network to reach a 100-year Centennial milestone.

New York↗

Glacier fed deltas and new age constraints for glacial Lake Grand Gorge in the northern Catskill Mountains of New York State, USA

Ice-dammed lakes were common along the southern margin of the Laurentide Ice Sheet during deglaciation. In the Schoharie Valley of the northern Catskill Mountains, New York, a 171 km 2 lake known as glacial Lake Grand Gorge formed in an interlobate area. Previous researchers suggested that deltas developed into this glacial lake from meltwater supplied by the adjacent Hudson Lobe during deglaciation. This study investigates stratigraphy and sedimentology of Pleistocene deltas and lake deposits to determine the source of meltwater and sediment. Detailed examination of stratigraphy from quarries, stream exposures, and new exploration borings was combined with radiocarbon and OSL geochronology to establish event stratigraphy. Sedimentologic and geomorphic data from deltas in the Manor Kill and Platter Kill Valleys demonstrates that braided outwash was supplied directly from the Westerlo Sublobe that crossed the northeastern escarpment of the Catskill Mountains. New geochronologic data indicates that the lake was established by 28 ka and likely persisted to at least 22 ka. Insects and twigs recovered from lake sediments complement the OSL data and indicate: (1) that the lake was present significantly earlier than previous deglacial models predict, and (2) that it existed in an ice-free area of the northern Catskill Mountains during the last glacial maximum of the MIS 2 glaciation.

New York↗

Temperate lake heatwaves accelerate non-linearly as timing synchronizes across a diverse landscape

Temperate lakes are experiencing intensifying heatwaves, or prolonged periods of anomalously warm water, with potentially severe ecological consequences. Previous studies have predominantly used linear trend analyses to understand heatwave dynamics, potentially masking temporal acceleration patterns and shifts in variance. Here, we analyzed long-term, nonlinear trends in heatwave frequency, intensity, and timing across 4391 New York lakes using simulated daily surface water temperatures from an Entity-Aware Long Short-Term Memory deep learning model (validated root mean square error = 1.82°C; 1980–2020). We applied generalized additive mixed models to quantify complex temporal patterns while accounting for lake-specific effects and environmental characteristics (lake surface area, elevation, and latitude). All heatwave metrics demonstrated nonlinear and dynamic temporal trends. Heatwave frequency showed early increases in the number of events (0.05–1.32 events during the 1980s) followed by accelerated growth after 2000; other metrics exhibited more complex decadal patterns. Temporal variance increased significantly for both heatwave frequency ( τ = 0.73, p < 0.001) and intensity ( τ = 0.33, p = 0.003). Lake characteristics drove some heatwave dynamics; smaller lakes experienced higher intensities and complex elevation-latitude interactions varying by heatwave metric. Spatial patterns revealed increasing heterogeneity for heatwave intensity and frequency while heatwave timing homogenized to earlier dates across the landscape. Our findings reveal nonlinear heatwave dynamics with increasing variability, which may reduce predictability and intensify ecological vulnerabilities beyond current projections.

New York↗

Hydrogeology of the Tully Valley and characterization of mudboil activity, Onondaga County, New York

Mudboil activity in the Tully Valley, in central New York, is causing turbidity in nearby Onondaga Creek, where it has caused a bridge to collapse; it also has threatened or damaged other structures and has caused extensive land subsidence. Mudboil activity was intermittent from its first reported appearance in the 1890's until the 1970's, when the rates of mudboil discharge and land subsidence began to increase. Historically, the water discharged from mudboils was reported as fresh, but chemical analyses in the late 1970's indicated an increase in specific conductance and chloride concentration. Mudboil discharge is driven by artesian pressure in unconsolidated sediments that are confined by a 60-foot layer of silt and red clay. This process, once begun, has been self-propagating. Artesian pressures are about 20 feet above land surface over most of the valley floor but exceed 30 feet above land surface along Onondaga Creek where Rattlesnake Gulf and Rainbow Creek enter the Tully Valley. The source of artesian pressure is recharge from the Tully (Valley Heads) Moraine at the south end of the valley, and the alluvial fans of Rattlesnake Gulf and Rainbow Creek. The mudboils are found within a 300-foot-wide by 1,500-foot-long corridor along Onondaga Creek just upstream from the two alluvial fans, and in a 5-acre subsided area just west of that corridor. Remediation efforts have entailed (1) diversion of flow from the tributary that feeds the subsided area, (2) installation of depressurizing wells at several locations, and (3) construction of a dam and settling impoundment to detain mudboil sediment that would normally discharge to Onondaga Creek. These efforts have been partly successful, but further work is needed to slow the mudboil activity, which is expected to persist in both areas. Mudboil activity is normally greatest during the early spring and late fall, when artesian pressures increase in response to seasonal ground-water recharge. Suspended-sediment concentrations at the out-flow of the subsidence area ranged from 31,210 mg/L (milligrams per liter) in October 1991 to 17 mg/L after remediation efforts in the summer of 1993. Yearly average suspended-sediment loads to Onondaga Creek from the subsidence area for water years 1992, 1993, 1994, and 1995 were 29.8, 9.75, 1.41, and 1.80 tons per day, respectively. Sediment discharged from the mudboils initially was 30 to 60 percent clay and 80 to 100 percent silt-sized or smaller sediment, and the sand fraction never exceeded 20 percent. After the remediation projects, 50 to 80 percent was clay, and nearly all sediment was silt size or smaller. Analyses of water from upstream and downstream of the subsidence area, as well as from mudboil vents within that area, indicate that the source of water for some mudboils is a confined freshwater aquifer, whereas for others it is an underlying, brackish-water aquifer. Water from the freshwater aquifer has specific conductance values ranging from about 400 ( μS /cm (microsiemens per centimeter at 25° Celsius) to almost 900 ( μS /cm, dissolved chloride concentrations range from 37 to 430 mg/L, and dissolved-solids concentrations range from 215 to 463 mg/L. Specific conductance of water from the brackish-water aquifer ranges from 17,000 to 28,000 ( μS /cm, chloride concentrations range from 2,000 to 7,100 mg/L, and dissolved-solids concentrations range from 4,200 to 12,800 mg/L. The largest landslide in New York State in the last 75 years occurred at the foot of Bare Mountain, 1 mile downstream from the mudboil area, in April 1993 and was the fourth in a series of slides that have occurred at the base of this hill. Slope instability was reported as early as May 1990. After the slide, intermittent mudboil-like activity was observed at several springs within the backscarp of the slide; water from these springs ranged from fresh to brackish. The chemical similarity between water from some springs in the backscarp area and water in the lower (brackish) aquifer beneath the mudboil area may indicate a hydraulic connection between this aquifer and the surficial deposits. Hydrologic changes in the valley during the last 100 years have been attributed to salt-solution mining in the upstream (southern) end of the valley. The removal of nearly 150 feet of salt from four evaporite beds in the Syracuse Shale of the Salina Group has caused the collapse of bedrock and unconsolidated deposits in and near the brine field, 3 miles south of the mudboil area. These collapses have created a hydraulic connection among bedding plane aquifers in the bedrock and increased the hydraulic connection with unconsolidated aquifers. The ground-water flow system after brine field closure in 1988 may have reached a new semiequilibrium, but mudboil activity will likely continue because artesian pressures remain. Whether mudboils were present before salt solution-mining began is unknown.

New York↗

Storm surge barriers reduce seaward sediment supply to lagoonal estuaries

Numerical simulations with realistic forcing of fixed infrastructure for a proposed storm surge barrier for a lagoonal estuary, Jamaica Bay (New York, USA), are analyzed during typical forcing conditions to assess alterations to flow and sediment transport with the barrier open. Lagoonal estuaries are shallow and have modest watershed freshwater and sediment inputs, so sediment delivery is primarily from offshore by tidal transport. The storm surge barrier infrastructure across the inlet channel reduces cross-sectional area and increases tidal velocities, increasing frictional and form drag. The overall reduction in tidal amplitude is about 1%, but the quarterdiurnal M 4 component decreases by 11%. The salinity and stratification in the estuary are only slightly modified by mixing by stronger velocities near the barrier. Sediment transport in the inlet scales approximately with tidal velocity cubed and net landward transport is driven by flood-dominant tidal asymmetry. Additionally, tidal asymmetry in the jet flow through barrier openings causes a divergence in sediment transport within several kilometers. The alterations to the tidal currents reduce sediment import to the bay by 20% for fine sand; transport of sediment with slower settling velocities is less affected, with reductions of 3% for medium silt and <1% for fine silt. The study examined tidal exchange with an open barrier, but the overall impact also depends on barrier operations during major storm events. The impacts of barrier infrastructure on lagoonal estuaries are distinct from other estuary types due to their modest freshwater input, predominance of tidal transport, and offshore sediment supply.

New York↗

Sex-specific Atlantic salmon upstream passage and fallback at a natural cascade after dam removal

In the Boquet River (NY, USA) a low-head dam set above a ~200-m bedrock cascade was removed in 2015. We used radio-telemetry to assess landlocked Atlantic salmon passage at the remaining cascade (2020, 2022). Across years, 52% of males (13/25) attempted cascade passage whereas females made no discernable attempts (0/11). Attempt probability increased with stream discharge and decreased with fish size, though overall passage success was low (1/36). Shallow depths—likely owing to an artificially widened channel—appear to be limiting passage. Additionally, we transported fish upstream but observed high fallback (72%) that was associated with fish size and energetic status. Following dam removal, this cascade continues to limit upstream passage resulting in increased vulnerability to angling during migratory delay. Overall, we highlight the importance of follow-up studies after dam removal, and that further modifications at this site may be required to improve passage.

New York↗

Shallow hydrogeologic framework of the Tully Valley mudboil area, Onondaga County, New York

Mudboils have been documented in the Tully Valley in southern Onondaga County, New York, since the late 1890s. Sediment-laden water from the mudboils flows into Onondaga Creek, which empties into Onondaga Lake at Syracuse 15 miles to the north. Turbidity from the mudboils has degraded the water quality of Onondaga Creek despite a series of mitigation efforts that began in the early 1990s. Turbidity mitigation actions presently (2025) being considered include creek relocation and offline sediment settling. In support of these proposed actions during 2021–23, the U.S. Geological Survey, in cooperation with the New York State Department of Environmental Conservation, U.S. Environmental Protection Agency, Onondaga Nation, Onondaga Environmental Institute, and Central New York Regional Planning and Development Board, collected and analyzed geologic, hydrologic, geophysical, and geotechnical data to characterize the shallow hydrogeology along four proposed creek-relocation paths and in the proposed offline settling basin area. The investigation indicated that the four proposed creek-relocation paths, two east of Onondaga Creek and two west of Onondaga Creek, are underlain by sediments including muck, alluvium, mudboil deposits, alluvial-fan sand and gravel, and lacustrine fines. The proposed excavations would penetrate partially to fully saturated conditions: generally, the water table is shallow near the creek and deep on the alluvial fans. The shallowest excavation, about 5 feet below land surface, would be near the creek and primarily in alluvium, and the deepest excavation, as much as 30 feet below land surface, would be in the alluvial-fan deposits. Brackish waters would be penetrated by proposed channel excavations on the eastern side of Onondaga Creek in an area downgradient from a potentially leaking historical salt-exploration borehole and near the main mudboil area. Excavation in these areas likely would provide a continuous source of brackish groundwater to the relocated creek. Proposed channel excavations of muck, soft to very soft lacustrine fines, and mudboil-type sediments in mudboil and suspected mudboil areas would pose an excavation and slope stability challenge and would have the greatest potential to create new mudboils. Proposed channel excavations below the water table on the Rattlesnake Gulf and Rainbow Creek alluvial fans would intercept groundwater and make the constructed streambank susceptible to seepage-induced slope instability. The substantial water-level fluctuation in the sediments of both alluvial fans would aggravate the stability condition. In addition, excavation on the Rattlesnake Gulf alluvial fan would have the potential to affect water-supply springs at the toe of the fan. The proposed offline settling basin area is in the northern part of the Rattlesnake Gulf alluvial fan. Natural and man-made diversions of Rattlesnake Gulf have resulted in saturated conditions in the general area of the proposed basin. The proposed offline settling basin would be excavated in, and berms would be constructed on, alluvial-fan deposits and lacustrine fines. In the proposed basin area, the alluvial deposits overlying the lacustrine fines are less than 10 feet thick. Excavation, berm construction, and loading of the saturated, soft to very soft lacustrine fines may be problematic and require soil strengthening.

New York↗

Hydrologic investigation of water level fluctuations at Moreau Lake, Moreau Lake State Park, town of Moreau, New York

The causes of water level fluctuations at Moreau Lake, within Moreau Lake State Park in the town of Moreau, New York, were investigated from 2016 to 2021 after lake water levels dropped between 2015 and 2016, raising concerns about the loss of a shallow swimming area at the park beach. Annual variation in precipitation records from the area did not account for the lake water level decline. Two possible causes for the low lake water levels were investigated: the increase in groundwater withdrawals from new residential development since about 2000 and seasonal changes (nongrowing and growing seasons) in precipitation. Investigation of the potential effects of nearby groundwater withdrawals required the compilation and collection of well-log data, seismic surveys, and measurements of lake and groundwater levels, field chemical parameters, and water isotopes to define the hydrogeologic system and to estimate water use. The net result of this work was the determination that Moreau Lake is a “flow though” lake with no surface water outlet; groundwater enters the lake on the upgradient side and exits through the downgradient side, however, groundwater does not flow southward from the lake toward nearby groundwater withdrawals from the semiconfined aquifer, and thus groundwater withdrawals were unlikely to have an effect on lake water levels. Investigation of the historic precipitation records during nongrowing (November through April) and growing (May through October) indicated that (1) nongrowing season precipitation from 2011–12 to 2015–16 was more deficient than any similar period during the past 78 years and (2) since about 2000, nongrowing seasons have been drier overall and growing seasons have been considerably wetter. Initiation of lake water level monitoring in 2016 provided an opportunity to compare seasonal precipitation with seasonal lake water level changes. Nongrowing season lake water levels are very sensitive to precipitation, such that high precipitation (40 percent above the seasonal median) resulted in a 5-foot rise in lake water level. In contrast, the growing season lake water levels are sensitive to dry conditions; for example, deficient rainfall (about 6 percent below the seasonal median) resulted in a decline of lake water levels of about 3.5 feet. However, lake water levels are insensitive to high growing season rainfall inputs (about 10 to 47 percent above the seasonal median); lake water levels consistently declined about by 0.8 feet above this range of seasonal excessive precipitation.

New York↗