TO WHOM IT MAY CONCERN: Comments are invited on the work described below. Please see the Public Involvement section for details on submitting comments.
Point of Contact. If additional information is desired, please contact the regulator, Austin Dartez, telephone number: 501-690-6182, mailing address: Little Rock District Corps of Engineers, Regulatory Division, PO Box 867, Little Rock, Arkansas 72203-0867, email address: Austin.R.Dartez@usace.army.mil
Project Information. Pursuant to Section 404 of the Clean Water Act (33 U.S. Code 1344), notice is hereby given that
Lazendra Hairston-Barton
Arkansas Game and Fish Commission (AGFC)
2 Natural Resources Drive
Little Rock, AR 72211
has requested authorization for work, including the placement of dredged and fill material, in waters of the United States associated with drawing the lake down, upgrading the Lake Conway primary spillway, installing an auxiliary spillway, mulching vegetation within established and new recreational boat lanes, marking boat lanes with utility poles, and removing one existing boat ramp. The proposed project is located in Lake Conway, in Mayflower and Conway, Faulkner County, Arkansas.
The project purpose is to enhance the ability to recreate within and maintain Lake Conway, by updating the flood control structures to modern standards and to improve recreational abilities in the lake by enhancing and creating boat lanes.
The overall project consists of multiple phases, specifically including drawing down the lake level to facilitate construction, preparing the spillway and boat lanes project areas, performing the work, and then reestablishing the lake level. There will be no change to the normal pool elevation of the lake. The overall project is expected to include approximately 5 years of periodic work; the boat lanes portion is expected to take approximately 6 months and the spillway portion is expected to take approximately 2 years. The lake drawdown is currently ongoing while the lake is expected to remain navigable for recreation in main channels during the duration of this project. However, the area near the current spillway will be inaccessible during the construction of the main and auxiliary spillways (estimated to last 24 months) and is expected to remain inaccessible for the duration of the project, approximately five years overall (September 2028). Side channel depths will likely remain too low for recreational activities during the entire duration of this project and should be assumed to be closed to boat traffic.
Preparatory work for the primary and auxiliary spillways will include the overall lake draw down, installation of erosion controls to prevent accidental translocation of fill material into the lake per the applicants Storm Water Pollution Prevention Plan and Construction Stormwater Permit, installation of three temporary cofferdams to dewater the work and fill areas in periodic phases, removing a portion of the primary existing spillway structure, and removing one existing boat ramp located along the northern portion of the existing access road for the existing primary spillway and dam. Preparatory work for the boat lanes will only consist of the overall drawdown of the lake.
The improved primary spillway component of the project consists of partially removing and disposing of portions of the existing 15-gate manually-controlled spillway structure in Palarm Creek and constructing a trapezoidal labyrinth weir within the same general footprint. Additionally, the existing concrete apron for the spillway will be extended. The proposed new concrete apron, which will serve as the foundation for the new weir and scour protection immediately downstream of the weir, will be constructed and will extend about 144 linear feet beyond the edge of the existing apron. Riprap channel armoring will extend for an additional 50 linear feet downstream of the new concrete apron. The total fill area for the new spillway structure and concrete apron extension is 0.16-acres within waters. Additionally, riprap will be placed downslope of the concrete apron and along the adjacent northern bank of Palarm Creek, within a 0.30-acre footprint within waters. The riprap and concrete apron downstream of the primary spillway are proposed to be at maximum, 3 feet deep from the stream bed, and below the ordinary high-water mark within the central portion of the stream to facilitate aquatic life passage and decrease potential adverse ecological effects. The entire new permanent fill area for the primary spillway portion of the project within waters, including the riprap associated with both spillways, is 0.46-acres (2,065 cubic yards of fill).
The auxiliary spillway structure portion of the project consists of a new auxiliary control structure to be installed within Lake Conway at the Lake Conway dam, northwest of the existing primary spillway, and will discharge to Palarm Creek when the lake level exceeds normal pool (El 263.0). The structure is proposed to consist of uncontrolled concrete trapezoidal labyrinth spillway, comprised primarily of a riprap scour pad at the entrance to the spillway, an uncontrolled concrete spillway, and a concrete apron terminating where riprap will be placed at the northern bank of Palarm Creek (previously discussed above). The structure also is proposed to include six 8-foot-wide by 6-foot-high sluice gates, which can be used for management drawdowns, and hydraulic engineering control elements (aluminum stoplogs) in two of the structures side walls, to allow AGFC to temporarily lower the lake level to an elevation below normal pool. The capacity of the sluice gates discharge is approximately equivalent to the existing gated primary spillway discharge. The riprap scour pad at the mouth of the structure consists of 0.32-acres of fill material placed within waters and the concrete spillway consists of 0.08 acres of fill within waters. The entire new permanent fill area for the auxiliary spillway portion of the project within waters, not including the riprap associated with both spillways (included above), is 0.40-acres (2,285 cubic yards of fill).
Further, to inhibit floating surface and near surface debris (e.g., logs, limbs, trash, etc.) from passing through the auxiliary spillway, a floating debris boom and screen will be installed. This structure will be permanently placed in the lake upstream of the new auxiliary spillway structure and will terminate at the existing debris fence for the primary structure. The floating debris boom and screen will consist of a stainless steel (or equivalent) frame and mesh for the protection of boaters. Signage will be installed at a reasonable distance from the spillway structures offshore, per U.S. Coast Guard requirements.
The boat lane creation and enhancement portion of the project consists of enhancing existing boat lanes and establishing new boat lanes by mulching submerged tree stumps below the waterline. Currently, there are numerous submerged trees within the existing boat lanes, which are hazards to recreational activities. The boat lanes will be established along predetermined and existing paths. The new predetermined paths will be moved further out from shore than existing boat lanes to minimize shoreline erosion.
Wooden utility poles (approximately 6-inches in diameter and 20-30 feet long) will be utilized to mark the edge of the boat lanes, and will be spaced approximately 75-100 yards apart, and 5 feet inside the boat lane edge. Within boat lanes, the poles will be installed at 6 feet above normal lake pool levels, and at the intersection of boat lanes poles will be installed at 8 feet above normal lake pool levels. A total of approximately 3,000 utility poles used to mark the boat lanes. These will be placed by using either vibration techniques or with a hydraulic hammer. A total of 30.61 miles of boat lanes will be maintained. The majority of the boat lanes (27.8 miles) will be cleared to 60 feet wide. Two segments (2.4 miles) of existing 100-foot-wide boat lanes will be cleared. One segment (0.41 mile) of functional boat lane was created by a tornadic event; this area will not be marked with utility poles, but submerged vegetation will be cleaned up for safety. The new lanes will be created in the fingers of the lake to allow for safer unmotorized boater access and use. The boat lane design has been laid out to maximize the safety of boaters that are idle fishing while other boaters are navigating in the lanes. Work within the boat lanes will be done using various mulching machinery, potentially including tracked, wheeled, and amphibious (low ground pressure) configurations. Approximately 10% of the mulching will be undertaken in 0-3 feet of standing water with excavators transported and employed from barges.
AGFC owns, operates, and maintains Lake Conway, an approximately 5,900-acre reservoir, located in Faulkner County, AR. The reservoir was originally impounded in 1948 by construction of an earthen dam and spillway across Palarm Creek, a tributary to the Arkansas River.
In 2018 a feasibility study was conducted by AGFC’s engineering consultant, to model and develop conceptual alternatives for a spillway modification at the lake. AGFC's goal is to replace or supplement the existing gated spillway with an uncontrolled outfall system that would allow the maintenance of a normal pool at a static elevation without requiring manual operation of gates prior to or during storm events to regulate lake levels. Currently, the system requires the manual operation of gates in order to reduce the potential for shoreline residential flooding, as well as to eliminate the need for a lake drawdown to provide additional flood storage during the winter/spring wet season. Proposed modifications would be expected to result in an uncontrolled lake level management system such that water levels during storm events would be no greater than are achieved with the current manual regulation for the design storm. In addition, it is desired that the new system provides the potential for a higher discharge capacity, as well as provide for the ability to conduct lake management drawdowns. An additional benefit of such a modification would be potentially providing some level of flood relief for properties along the shoreline that are reportedly flooded periodically as a result of high lake levels during significant hydrologic events.
AGFC has provided the following statement, regarding the planned steps to avoid and minimize impacts to the aquatic environment: “The project has been designed to avoid and minimize impacts to waters of the United States by avoiding wetlands and utilizing BMPs during construction. The only proposed permanent fills are related to the spillway construction and are unavoidable. The boat lanes portion of the project will result in fills due to the placement of mulched material; however, no net loss of waters is expected due to these fills, as the material is merely being dispersed within the same resource.”
AGFC has not proposed compensatory mitigation for permanent fills associated with the spillway portion of the project. Should the proposed undertaking be found to cause more than minimal losses of waters, compensatory mitigation required to offset environmental losses resulting from unavoidable impacts to waters of the United States will be addressed following the mitigation hierarchy as outlined within the 2008 Compensatory Mitigation Rule (33 CFR Parts 325 and 332).
The location and general plan for the proposed work are shown on the enclosed sheets (Sheets 1-7 of 7).
Water Quality Certification. The Clean Water Act (CWA) Section 401 Certification Rule (Certification Rule, 40 Code of Federal Regulations (CFR) Part 121), effective November 27, 2023, requires certification for any license or permit that authorizes an activity that may result in a discharge. The scope of a CWA Section 401 certification is limited to assuring that a discharge from a Federally licensed or permitted activity will comply with water quality requirements. The applicant is solely responsible for requesting certification and providing required information to the certifying agency. As of the date of this public notice, the applicant has not submitted a certification request to the Arkansas Department of Energy and Environment, Division of Environmental Quality (certifying authority). In accordance with Certification Rule Part 121.6, the Corps and ADEQ have determined the reasonable period of time for the certifying agency to act upon the certification request is 180 days once the applicant submits a certification request to the certifying agency. In accordance with Certification Rule Part 121.12, the Corps will notify the U.S. Environmental Protection Agency Administrator when it has received the subject certification. The Administrator is responsible for determining if the discharge may affect water quality in a neighboring jurisdiction. The DA permit may not be issued pending the conclusion of the Administrator’s determination of effects on neighboring jurisdictions.
Cultural Resources. A Corps staff archeologist will evaluate the proposal for compliance with Section 106 of the National Historic Preservation Act, including identification and evaluation of cultural resources potentially impacted by the proposal's implementation in waters of the United States. The District Engineer invites responses to this public notice from Native American Nations or tribal governments; Federal, State, and local agencies; historical and archeological societies; and other parties likely to have knowledge of or concerns with historic properties in the area.
Endangered Species. Our preliminary determination is that the proposed activity may affect, but is not likely to adversely affect, the Proposed Threatened Alligator Snapping Turtle (Macrochelys temminckii) but will not affect any other listed Endangered Species or critical habitat for listed Endangered Species. A copy of this notice is being furnished to the U.S. Fish and Wildlife Service and appropriate state agencies and constitutes a request to those agencies for information on whether any listed or proposed‑to‑be‑listed endangered or threatened species may be present in the area which would be affected by the proposed activity.
Floodplain. We are providing copies of this notice to appropriate floodplain officials in accordance with 44 Code of Federal Regulations (CFR) Part 60 (Floodplain Management Regulations Criteria for Land Management and Use) and Executive Order 11988 on Floodplain Management. The project is known to the Corps to be within a Special Flood Hazard Area (Zone AE).
Section 404(b)(1) Guidelines. The evaluation of activities to be authorized under this permit, which involves the discharge of dredged or fill material will include application of guidelines promulgated by the Administrator, Environmental Protection Agency, under authority of Section 404(b) of the Clean Water Act. These guidelines are contained in 40 Code of Federal CFR 230.
Public Involvement. Any interested party is invited to submit to the above-listed POC written comments or objections relative to the proposed work on or before June 7, 2024. Substantive comments, both favorable and unfavorable, will be accepted and made a part of the record and will receive full consideration in determining whether this work would be in the public interest. The decision whether to issue a permit will be based on an evaluation of the probable impact including cumulative impacts of the proposed activity on the public interest. That decision will reflect the national concern for both protection and utilization of important resources. The benefit, which reasonably may be expected to accrue from the proposal, must be balanced against its reasonably foreseeable detriments. All factors which may be relevant to the proposal will be considered including the cumulative effects thereof; among those are conservation, economics, aesthetics, general environmental concerns, wetlands, historic properties, fish and wildlife values, flood hazards, floodplain values, land use, navigation, shoreline erosion and accretion, recreation, water supply and conservation, water quality, energy needs, safety, food and fiber production, mineral needs, considerations of property ownership and, in general, the needs and welfare of the people.
The Corps of Engineers is soliciting comments from the public; Federal, state, and local agencies and officials; Indian Tribes; and other interested parties in order to consider and evaluate the impacts of this proposed activity. Any comments received will be considered by the Corps of Engineers to determine whether to issue, modify, condition or deny a permit for this proposal. To make this decision, comments are used to assess impacts on endangered species, historic properties, water quality, general environmental effects, and the other public interest factors listed above. Comments are used in the preparation of an Environmental Assessment and/or an Environmental Impact Statement pursuant to the National Environmental Policy Act. Comments are also used to determine the need for a public hearing and to determine the overall public interest of the proposed activity.
Any person may request in writing within the comment period specified in this notice that a public hearing be held to consider this application. Requests for public hearings shall state, with particularity, the reasons for holding a public hearing. The District Engineer will determine if the issues raised are substantial and whether a hearing is needed for making a decision.
NOTE: The mailing list for this Public Notice is arranged by state and county(s) where the project is located, and includes any addressees who have asked to receive copies of all public notices. Please discard notices that are not of interest to you. If you have no need for any of these notices, please advise us so that your name can be removed from the mailing list.
Enclosures:
Approximate Coordinates of Project Center
Latitude: 35.005252° Longitude: -92.394601°
UTM Zone: 15S North: 3873792.91 East: 555240.48