Search USGS⌕ Search

Geology topics

Research about Mohawk River

Source-linked reports with geographic coverage including Mohawk River.

8 recordsLinked to original sources
USGS2026

Investigation of fish communities in natural channel sections of the Mohawk River, New York

Little is known about the natural resources in the natural channel sections of the Mohawk River between Rome and Frankfort, New York, where the river channel runs separately from and parallel to the Erie Canal. This river section runs through multiple locations that are listed as active remediation sites under New York’s Inactive Hazardous Waste Disposal Site Program and has negligible public or commercial access. As a result, there is minimal recreational usage of this river section, and efforts to conduct biological sampling have been limited. To better understand the composition of fish communities and contaminant concentrations in the natural channel of the Mohawk River, the U.S. Geological Survey, in cooperation with the New York State Department of Environmental Conservation, sampled resident fish in the 34-kilometer section from the mouth of Oriskany Creek downstream to Frankfort. Fish communities were sampled using boat electrofishing during 2021, 2023, and 2024 across multiple reaches within this section. These data were used to estimate species richness (number of species), relative abundance and biomass (catch rates), population size structure (distribution of lengths), and fish condition (a proxy for health). Some gamefish specimens were also analyzed to determine contaminant concentrations in fish tissue. A total of 1,531 individual fish and 38 fish species were captured across all surveys. Seventeen of the 38 (45 percent) species were classified as native to the Mohawk River watershed, whereas 21 of the 38 (55 percent) species were classified as nonnative. Some popular gamefish species such as largemouth bass ( Micropterus salmoides ) and smallmouth bass ( Micropterus dolomieu ) were abundant in most reaches, whereas others such as walleye ( Sander vitreus ) and northern pike ( Esox lucius ) were found sporadically. Only one round goby ( Neogobius melanostomus ) was captured, indicating that this high-profile invasive species remains uncommon in this habitat. A backwater reach had the greatest relative abundance and condition of many species. This indicates connected lentic habitats such as oxbows and backwaters may be important nursery and refuge areas in the aquatic ecosystem. Polychlorinated biphenyl (PCB) concentrations in fish tissue were highly elevated relative to the New York State Department of Health (NYSDOH) fish consumption “don’t eat” advisory guideline. Some specimens exceeded the guideline by an order of magnitude or more, particularly those from a localized area downstream from the Utica Harbor Dam. Concentrations of perfluorooctanesulfonic acid (PFOS) often approached the NYSDOH “don’t eat” consumption guideline but only one sample exceeded the guideline. Concentrations of other contaminants such as mercury and pesticides were consistently measured at less than the “don’t eat” consumption guidelines. These data indicate PCBs remain the primary contaminant of concern in the natural channel of the Mohawk River and are readily bioaccumulating in aquatic organisms despite prior remediation measures. Taken together, the findings in this report are intended to inform future decisions related to fisheries management, public access, recreational usage, and fish consumption advisories.

New York↗
USGS2024

Development and calibration of HEC–RAS hydraulic, temperature, and nutrient models for the Mohawk River, New York

In support of a preliminary analysis performed by New York State Department of Environmental Conservation that found elevated nutrient levels along selected reaches of the Mohawk River, a one-dimensional, unsteady hydraulic and water-quality model (Hydrologic Engineering Center River Analysis System Nutrient Simulation Module 1 [HEC–RAS NSM I]) was developed by the U.S. Geological Survey for the 127-mile reach of the Mohawk River between Rome and Cohoes, New York. The model was designed to accurately simulate within-channel flow conditions for this highly regulated, control-structure dense river reach. The model was calibrated for the period of May through September 2016 using available streamflow, temperature, and water-quality data. Nitrogen, phosphorus, dissolved oxygen, and water column algae were balanced within the model; however, the nutrient model calibration was focused on phosphorus. The HEC–RAS hydraulic model simulated streamflow adequately at the calibration locations with observed and simulated daily flows demonstrating coefficient of determination ( r 2 ) values ranging from 0.91 to 0.97, mean absolute error ranging from 15–20 percent, and bias ranging from −7 to 16 percent. The water temperature model within HEC–RAS NSM I demonstrated remarkable ability to simulate water temperature: typical water temperature errors were less than 1.0 degree Celsius (°C). Simulated water temperature results closely tracked observed continuous water temperature data at three locations on the Mohawk River, with mean absolute error for the 2016 study period ranging from 0.87 to 0.90 °C, and a root mean square error of 1.00 to 1.07 °C. Performance criteria for the water-quality (nutrient) model were applied differently than the water temperature model because of the temporally coarse discrete samples collected for the project. The average difference between final simulated concentrations and observed concentrations of organic phosphorus for all sample locations was within 0.01 milligrams per liter (mg/L) and within 0.09 mg/L for orthophosphate using all locations except Rome, which was within 0.25 mg/L. The calibrated model was used to implement nine phosphorus reduction scenarios by applying reductions to wastewater treatment plant effluent concentrations within the model. Monthly mean differences were computed for five comparison locations. Scenario results were generally linear and predictable; scenarios implementing the highest reductions showed correspondingly larger differences in Mohawk River concentrations downstream from the wastewater treatment plants associated with those reductions. The largest monthly mean differences were realized from reduction scenario nine and ranged from −0.018 to −0.076 mg/L for organic phosphorus and from 0.001 to −0.138 mg/L for orthophosphate.

New York↗
USGS2024

United States Geological Survey ice jam monitoring network on the Mohawk River in Schenectady, NY

The United States Geological Survey (USGS) has continuously monitored the Mohawk River between Lock 7 and Lock 9 of the New York State Barge Canal since 2011. There was a brief period, from 1914 to 1919, when a streamgage was operated at Vischer Ferry Dam (Lock 7), however, frequent damage to the gage from ice-jam related flooding in 1914 (figure 1) and 1916 resulted in establishing the Mohawk River streamgage at Cohoes, NY (USGS station ID 01357500) in 1917 and discontinuing the Vischer Ferry streamgage in 1919. The current monitoring network includes measurements of gage height (water level) and water temperature at various points within the reach, streamflow at Freeman’s Bridge, and realtime imagery from multiple pan-tilt-zoom web cameras, all of which provide situational awareness to the public, emergency managers, and other stakeholders during periods of ice-jam flooding. The USGS operates and maintains these stations in cooperation with the New York Power Authority, New York State Department of Environmental Conservation, Union College, and Brookfield Renewable Power.

New York↗
USGS2023

Use of environmental DNA to assess American Eel distribution, abundance, and barriers in a river-canal system

Objective: The American Eel Anguilla rostrata historically was one of the most common fish species in Atlantic coast watersheds, but extensive dam construction and other factors caused a widespread population decline. One of the watersheds where American Eels have declined considerably is the Mohawk River in eastern and central New York. Recent attempts to characterize the distribution and abundance of American Eels in this watershed have been ineffective, and the extent to which a series of locks and dams on the Hudson River and lower Mohawk River limits use of the watershed is unclear. Methods: We developed a model between environmental DNA (eDNA) quantity and American Eel abundance in the Hudson River watershed in which the DNA concentration in water samples explained up to 65% of the variability in eel density and 56% of the variability in eel biomass. We then used this relationship to interpret eDNA data collected twice from 36 sites across the Mohawk River watershed in 2021 and make inferences about the distribution and abundance of American Eels. Result: American Eel DNA was detected almost exclusively in the downstream-most 4 km of the Mohawk River within a series of barriers. The concentration of DNA was reduced by approximately 80% across each successive upstream barrier before becoming too low to detect consistently. Our data suggest that eel population density was high in the Hudson River estuary and declined rapidly in the lower Mohawk River, and the species was nearly absent or undetectable in the Mohawk River and its tributaries upstream of the Crescent Dam and the Waterford Flight of Locks. Conclusion: Barriers appear to be largely restricting American Eels from using over 99% of the Mohawk River watershed. Therefore, improvements in fish passage at dams and hydroelectric facilities in the region could help the American Eel to regain access to this part of its native range.

New York↗
USGS2017

Effects of extreme floods on macroinvertebrate assemblages in tributaries to the Mohawk River, New York, USA

Climate change is forecast to bring more frequent and intense precipitation to New York which has motivated research into the effects of floods on stream ecosystems. Macroinvertebrate assemblages were sampled at 13 sites in the Mohawk River basin during August 2011, and again in October 2011, following historic floods caused by remnants of Hurricane Irene and Tropical Storm Lee. The annual exceedance probabilities of floods at regional flow-monitoring sites ranged from 0.5 to 0.001. Data from the first 2 surveys, and from additional surveys done during July and October 2014, were assessed to characterize the severity of flood impacts, effect of seasonality, and recovery. Indices of total taxa richness; Ephemeroptera, Plecoptera, and Trichoptera (EPT) richness; Hilsenhoff's biotic index; per cent model affinity; and nutrient biotic index-phosphorus were combined to calculate New York State Biological Assessment Profile scores. Analysis of variance tests were used to determine if the Biological Assessment Profile, its component metrics, relative abundance, and diversity differed significantly ( p ≤ .05) among the four surveys. Only total taxa richness and Shannon–Wiener diversity increased significantly, and abundance decreased significantly, following the floods. No metrics differed significantly between the July and August 2014 surveys which indicates that the differences denoted between the August and October 2011 surveys were caused by the floods. Changes in taxa richness, EPT richness, and diversity were significantly correlated with flood annual exceedance probabilities. This study increased our understanding of the resistance and resilience of benthic macroinvertebrate communities by showing that their assemblages were relatively impervious to extreme floods across the region.

New York↗
USGS1978

Supplementary hydraulic analysis of proposed bridge site on Mohawk River, Whitesboro, New York

As a supplement to a 1975 report, titled "Floodflow Characteristics at Proposed Bridge Site on Mohawk River, Whitesboro, New York," by Bernard Dunn (U.S. Geological. Survey open-file report), in which the hydraulic effects of two alternative highway plans during a large-magnitude flood were evaluated, a hydraulic analysis was made for a third highway plan. The two plans evaluated in the original report had been found by the State Department of Transportation to be infeasible. A design-flood discharge of 18,200 cubic feet per second was used in the new evaluation, as in the original report. The recurrence interval of that flood is approximately 100 years. The corresponding peak flood stage at the proposed bridge site was determined by the New York State Department of Transportation to be 411.8 feet. During the design flood, the new proposed alternative would cause a 0.1-foot increase in water-surface elevation from the bridge to the approach section; 1,300 cubic feet per second would overflow the road north of the bridge and 6,800 cubic feet per second south of it. Discharge through the bridge would be 10,100 cubic feet per second.

New York↗
USGS1975

Floodflow characteristics at proposed bridge sites on Mohawk River, Whitesboro, New York

An evaluation of floodflow characteristics at the proposed bridge site revealed that: 1.The design-flood discharge for the proposed bridge site would be 18,200 cubic feet per second (515 cubic metres per second), which is about equal to the discharge for the 100-year flood. 2.The elevation at the bridge site for the flood of October 2, 1945, was 411.8 feet (125.5 metres). 3.Alternate-bridge designs 1 and 2 would cause 0.2 foot (0.06 metre) increase in water level.

New York↗