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US Army Corps of Engineers
Great Lakes and Ohio River Division

Ohio River Water Quality

Water Quality Workshops

The Corps' Water Quality Program in the Ohio River region is responsible for the monitoring and management of water quality at reservoirs, lakes, tributaries and rivers that have Corps-operated structures for flood control and navigation. The Corps also monitors sediment and water quality in relation to dredging and dredged material placement and conducts water quality modeling and studies in cooperation with regional partners. In the Ohio River Region, the Corps' Water Quality Program is conducted by the four district offices shown on the map, with their Civil Works boundaries. 

These districts are responsible for a number of activities related to the management of water quality in the Ohio River and tributaries, including:

  • Monitoring
  • Restoration and Remediation
  • Modeling & Evaluation
  • Partnerships & Coordination
  • Data Management
  • Reporting


The Corps of Engineers conducts a variety of monitoring at water resource projects in order to assess and maintain water quality conditions:

  • Lake and Reservoir Monitoring
  • Sediment Pollutant Monitoring
  • Macroinvertebrate Surveys
  • Algal Surveys
  • Bacterial Monitoring
  • Zebra Mussel Monitoring

- Lake and Reservoir Monitoring

  • The Corps of Engineers monitors water quality at reservoirs to determine when and where conditions are approaching State established standards or project-specific water quality objectives. Monitoring stations include the pool above the dam (headwater), major tributaries and inflows, releases at the dam, and the tailwater downstream of the dam. The monitoring data is used in conjunction with computer models or other tools to determine what changes to the operation of dams and hydropower facilities are needed to maintain or restore water quality conditions.

- Sediment Pollutant Monitoring

  • Since 1984, Corps districts have monitored bottom sediments from lakes and reservoirs for priority pollutants on a 5-year rotational basis. Bottom sediments are a natural "sink" for many toxic and persistent pollutants that are hard to detect in the water column. This program has been successful at establishing baseline data for some water quality parameters and assessing damages caused by spills and changes to pollutant loadings. Sediments are typically analyzed for grain size, nutrients, selected metals, and priority pollutants.
  • The Corps also conducts sampling and testing of sediments from Federal navigation channels that are proposed for dredging in order to evaluate options for disposal of the dredged material and to comply with State water quality certification requirements. Dredged material testing and evaluation is conducted in accordance with the Inland Testing Manual, developed by the USEPA and Corps of Engineers.

- Macroinvertebrate Surveys

  • Corps districts collect samples of macroinvertebrates in the early Fall from sites located in the head- and tailwaters of lake projects. In lakes, habitats suitable for macroinvertebrates are generally found in shallower regions along the shoreline. Selected substrates included gravel, rock, silt, and vegetation.

- Algal Surveys

  • Algae are continuously exposed to their aquatic environment, have short generation times, rapid community response times, and are excellent biological indicators of water quality. Suspended algae, called phytoplankton, are distributed throughout the lake and may be easily collected from different depths using a water sampling bottle. In addition to samples used for examination of the algal cells, samples are also collected for analysis of chlorophyll a.

- Bacterial Monitoring

  • No additional information at this time.

- Zebra Mussel Monitoring

  • A surveillance program is being conducted for evaluation of existing and potential problems with zebra mussels at Corps projects in the Ohio River Basin. The program includes routine inspection of all visible surfaces for zebra mussels and for damage associated with zebra mussel attachment; implementation of protective measures, if effective and possible; assurance of continued operation of stream gages and water quality monitors in contact with raw water; continued reservoir surveillance and monitoring; provision of public information programs on zebra mussels; and field demonstrations of treatment technologies developed by the Corps and other agencies.

Modeling and Evaluation

The Corps of Engineers water quality modeling on the Ohio River began over 30 years ago with some of the first applications ever made for operating water control structures on a river/reservoir system. Today, the four districts in the Ohio River Basin command expertise in a variety of models developed by the Corps and applied on the Ohio River and its tributaries, including CE-QUAL.-W2 and WQRRS. Models have been used for pre-impoundment studies on the impacts of proposed reservoirs, post-impoundment studies on how changes to operations of existing reservoirs will impact water quality, and for real-time management of water quality in some parts of the system.

Much of the Corps water quality monitoring is conducted to collect data for the calibration of models for reservoirs or lakes. Modeling has received highest priority for projects where the Corps has the ability to make operational changes that can significantly impact water quality, such as reservoirs with selective withdrawal capability or hydropower facilities. Modeling has also been used to evaluate the impacts of basinwide conditions (e.g., drought), respond to chemical spills, and anticipate the impacts of major changes or repairs to water control structures. The Corps' water quality modeling efforts have received interest from other water resource agencies, and has resulted in several partnerships between the Corps and States and other Federal agencies. These partnerships include efforts to apply the Corps' models to Total Maximum Daily Load (TMDL) studies for waterway segments affected by discharges from Corps' dams.

Data Management

The Corps of Engineers does not have a centralized management system for water quality data. Each district has developed data management systems that satisfy their individual needs. A general description of the data management systems used by the districts in the Ohio River Basin is provided here.

Restoration and Remediation

No additional information at this time.

Partnerships & Coordination

The Corps is actively seeking partners for water quality monitoring, evaluations, restoration and remediation. These partnerships can promote better quality data, avoid duplication of effort, and create a broad-based support for watershed practices that will restore and protect water quality. Partnerships with States and local agencies can enable the Corps to apply additional Federal funds for cost-shared studies and projects.


Internally, water quality data and evaluations are sent to Corps' area offices for distribution to individual lake projects. Copies are also sent to State water quality agencies. Several districts have made portions of their water quality data available online


NOTICE: All data contained herein is preliminary in nature and therefore subject to change. The data is for general information purposes ONLY and SHALL NOT be used in technical applications such as, but not limited to, studies or designs. All critical data should be obtained from and verified by the United States Army Corps of Engineers, Great Lakes and Ohio River Division, Water Management Team, 550 Main Street, Cincinnati, OH 45202. The United States of America assumes no liability for the completeness or accuracy of the data contained herein and any use of such data inconsistent with this disclaimer shall be solely at the risk of the user.

The appearance of external hyperlinks does not constitute endorsement by the United States Army Corps of Engineers (USACE) of the linked websites, or the information, products or services contained therein. For other than authorized activities such as military exchanges and Morale, Welfare and Recreation (MWR) sites, USACE does not exercise any editorial control over the information you may find at these locations. All links provided are consistent with the mission of this website.