E6-10015. Tongue River Watershed, Cavalier and Pembina Counties, ND

AGENCY:

Natural Resources Conservation Service, USDA.

ACTION:

Notice of a Finding of No Significant Impact.

SUMMARY:

Pursuant to Section 102(2)(c)of the National Environmental Policy Act of 1969; the Council on Environmental Quality Regulations (40 CFR Part 1500); and the Natural Resources Conservation Service, U.S. Department of Agriculture, gives notice that an environmental impact statement is not being prepared for the Tongue River Watershed, Cavalier and Pembina Counties, North Dakota.

FOR FURTHER INFORMATION CONTACT:

James E. Schmidt, Assistant State Conservationist for Water Resources, Natural Resources Conservation Service, 220 E. Rosser Avenue, Bismarck, North Dakota, at [phone].

SUPPLEMENTARY INFORMATION:

The environmental assessment of this federally assisted action indicates that the project will not cause significant local, regional, or national impacts on the environment. As a result of these findings, J.R. Flores, State Conservationist, has determined that the preparation and review of an environmental impact statement are not needed for this project.

The project purpose is to bring Tongue River Watershed Structure M-4 into compliance with current State and Federal dam design and safety criteria; to continue to provide flood protection and to reduce the risk of loss of human life. The planned works of improvement include rehabilitating and upgrading Renwick Dam by installing a roller compacted concrete auxiliary spillway, raising the top of the dam, and modifying the principal spillway to allow a one foot rise to the permanent pool to provide for sediment storage for the extended life of the structure. A two lane access road connecting recreation facilities on the north side of the lake to Icelandic State Park Headquarters on the south side of the park will be constructed on the upstream side of the embankment.

The Notice of a Finding of No Significant Impact (FONSI) has been forwarded to the Environmental Protection Agency and to various Federal, State, and local agencies and interested parties. A limited number of copies of the FONSI are available to fill single copy requests at the above address. Basic data developed during the environmental assessment are on file and may be reviewed by contacting James E. Schmidt, Assistant State Conservationist for Water Resources at [phone].

No administrative action on implementation of the proposal will be taken until 30 days after the date of this publication in the Federal Register.

James E. Schmidt,

Assistant State Conservationist for Water Resources.

Finding of No Significant Impact for Tongue River Watershed Cavalier and Pembina Counties, North Dakota

Introduction

The Tongue River Watershed is a federally assisted action authorized for planning under Public Law 83-566, the Watershed Protection and Flood Prevention Act. An environmental assessment was undertaken in conjunction with the development of Supplement No. 2 of the watershed plan for the purpose of rehabilitating Renwick Dam 9 (Structure M-4) under Public Law 106-472. This assessment was conducted in consultation with local, State, and Federal agencies as well as with interested organizations and individuals. Data developed during the assessment are available for public review at the following location: U.S. Department of Agriculture, Natural Resources Conservation Service, 220 E. Rosser Ave., P.O. Box 1458, Bismarck, North Dakota 58502-1458.

Recommended Action

Proposed is the rehabilitation of aging flood water retarding structure (M-4) in the Tongue River Watershed (Renwick Dam). This structure will provide flood control for downstream farms, cropland, roads, bridges, and the city of Cavalier. The structure will control 93,300 acres of drainage area. The recommended plan consists of constructing a roller compacted concrete (RCC) spillway through the existing dam with the park entrance road, on the face of the dam, on the upstream side. The RCC spillway's purpose is to convey the design flood runoff safely through the reservoir without overtopping the earthen embankment. A roller compacted concrete spillway is similar to conventional concrete, yet its material properties allow it to be worked and hauled by traditional earth moving equipment. The embankment will be partially excavated to design grades for construction of a 500-foot-wide auxiliary RCC spillway. The RCC spillway will be constructed as a broad-crested weir. Material excavated from the embankment to construct the spillway will be used as earth-fill to construct a dike in the existing auxiliary spillway and to raise the top of the embankment.

Effects of Recommended Action

The recommended action protects flood damages to building, transportation services land, crops, prime farmland, and the city of Cavalier. The economic and social well-being of the residents within and downstream of the watershed will remain intact. Renwick Dam provides an important recreation opportunity for the region. The recommended plan will meet the sponsor's objectives of bringing Renwick Dam into compliance with the current dam safety and flood insurance criteria, maintaining the current 100-year floodplain, and addressing the resource concerns identified by the public. As designed, Renwick Dam will meet all current NRCS and State of North Dakota dam safety and performance standards.

Studies were completed by both private contractors and State and Federal Agency personnel to evaluate the watershed water coming into and out of the Renwick and Senator Young Dams. Land cover surveys were completed to determine the need for additional land treatment practices in the watershed. A detailed study was completed to determine the existing depth of sediment load in the Renwick Reservoir. Also studied was the impact sediment disturbance would have on the reservoir fishery and other aquatic life. The study revealed Renwick Reservoir sediment pool is estimated to be 50-60 percent full. A water quality/sediment survey conducted in September 2003, indicated between 115 and 150 acre feet of sediment in the pool.

Preliminary investigations within the project area revealed no cultural or historic properties within the project area. Land disturbance has occurred through development of the area around the structure with the recreation area on the north side of the reservoir, and disturbance during the actual construction of the structure in the early 1960s. A summary of the project accompanied by maps and aerial photographs was provided to the North Dakota State Historic Preservation Office (SHPO) on August 31, 2001, with a request for concurrence. A passive concurrence from the North Dakota SHPO has been received. The probability of discovering a new site is low, but if there is a significant cultural resource discovery during construction, appropriate notice will be made by NRCS to the SHPO and the Tribal Historic Preservation Office (THPO). Consultation and coordination have been and will continue to be used to ensure the provisions of Section 106 of Public Law 89-665 have been met and to include provisions of Public Law 89-523, as amended by Public Law 93-291. NRCS will take action as prescribed in NRCS GM 420, Part 401, to protect or recover any significant cultural resources discovered during construction.

Threatened or endangered species may occasionally be present in the watershed but the project will have no adverse impacts on these species. Consultation with the U.S. Fish and Wildlife Service was completed.

No wilderness areas are in the watershed.

Scenic values will be temporarily decreased at the construction site. Once construction is complete, vegetation will enhance the site to its preconstruction condition.

No significant adverse environmental impacts will result from installations except for minor inconveniences to local residents during construction.

Alternatives

The planned action is the most practical means of reducing the high hazard dam problems. No significant adverse environmental impacts will result from installation of the measures. No other practical alternative achieved the economical, environmental, or social needs of the watershed land users or project sponsors. The no action alternative will not alleviate the dam from being a high hazard structure. The decommissioning of the dam will allow for severe flooding. The RCC auxiliary spillway with the park entrance on top of the Dam will meet the sponsor's needs, but the RCC auxiliary spillway with the park entrance on the upstream side of the dam face was chosen to be more economically feasible to the sponsors.

Consultation and Public Participation

Formulation of the alternative plan process for Renwick Dam began with formal discussions with the sponsors. At a special meeting held on March 6, 2001, NRCS conveyed State law and policy associated with high hazard dams. The National Dam Safety Inspection Reports of 1978, 1983, 1987, and 1991 listed Renwick Dam in the high hazard category for potential loss of life in the event of failure. Sponsors received information about agency policy associated with Public Law 106-472, The Small Watershed Rehabilitation Amendments of 2000, and related alternative plans of action.

As a result of these discussions, the sponsors submitted an application on March 14, 2001, to NRCS requesting assistance for rehabilitation of Renwick Dam under the provisions of Public Law 106-472.

A public meeting was held on April 16, 2002, to assess proposed measures and their potential impact on resources of concern. As a result of this meeting, fifteen items of concern were identified.

A meeting and field tour with the North Dakota Interagency Committee was held on June 18-19, 2002, to assess proposed measures and their potential impact on resources of concern.

A site visit with the NRCS National Water Management Center (NWMC) Staff, NRCS Planning Staff, and an engineer review team was held October 7, 8, and 9, 2002, to exchange a wide variety of ideas for the design.

The sponsors recognized the complexity of the project and on May 22, 2003, initiated and adopted a Watershed Management Council (WMC). The WMC membership is made up of one representative from each local organization, and city and county political authorities within the surrounding Cavalier and Pembina watershed area. Through detailed analysis and consultation it was agreed, an increase of the permanent pool by one foot would be necessary to maintain the same volume as that above the sediment pool. Removal of sediment was determined to be an unreasonable component of any proposed action due to a lack of safe disposal sites, high risk of not meeting Clean Water Act laws, and unpredictable costs per unit volume of sediment removed. It was also determined the volumes of sediment proposed to be removed would have little to no benefit towards flood storage and reducing the amount of rehabilitation work required to bring the structure into compliance with the Federal Dam Safety Program. Eleven alternatives were considered with all eleven being analyzed of having a one foot rise above the current elevation. All these alternatives were considered in the evaluation process by NRCS, project sponsors, Federal, State, and county agencies who were involved in part or all of the planning processes related to Supplement No. 2, the proposed rehabilitation of Flood Water Retarding Structure M-4.

Conclusion

The environmental assessment summarized above indicates this Federal action will not cause significant local, regional, or National impacts on the environment. Therefore, based on the above findings, I have determined that an environmental impact Statement for the Tongue River Watershed (Renwick Dam), Supplement No. 2 is not required.

Dated: June 15, 2006.

James E. Schmidt,

Assistant State Conservationist for Water Resources.