Westman Dam O

OPERATION, MAINTENANCE, AND MANAGEMENT PLAN

WESTMAN (HAYWARD LAKE) DAM AND IMPOUNDMENT

WALTON RIVER, LAKE MICHIGAN BASIN

DAM ID NUMBER: 00217

FEBRUARY 2023

LOCATION

Menominee County Township 35 North, Range 25 West, Section 18 Approximate Acreage Impounded: 740 Maximum Head of Water: 5 feet

Drainage Area: 49.6 square miles

DESCRIPTION AND HISTORY

The Michigan Department of Natural Resources (MDNR) installed a dam on the Walton River in 1952, presumably to stabilize water levels in Hayward and North Lakes and to expand the existing wetland complex for enhancement of wildlife habitat and recreation. The Westman Dam is a 161-foot earth-fill embankment with a structural height of 9.5 feet. The embankment consists of unspecified earth fill with upstream and downstream slopes of 3 horizontal to 1 vertical and a top width of 16 feet. Grasses and brush cover both slopes.

Design plans indicate the foundation material consists of 3 to 4 feet of cobble, boulder, and sand over clay material. Design plan notes indicate that unsuitable material was to be excavated prior to placement of embankment fill. The concrete spillway is founded on 2 separate rows [1 upstream, 1 downstream] of 8 gauge continuous interlocking steel sheet piling, 4 feet long and six 6 feet long, respectively.

When all stoplogs are in place, the dam creates a head of 5 feet and an impoundment with a surface area of about 740 acres. This “impoundment” is largely a widening and deepening of the Walton River between the dam and County Road G-12. If North, Little, and Hayward Lakes are considered part of the impoundment, then the total acreage is about 1,800 acres. However, elevation measurements obtained by MDNR land surveyors suggest the dam is not capable of influencing water levels on the greater portion of North, Little, and Hayward Lakes.

The primary spillway for the Westman Dam consists of a 5-bay, straight drop chute, concrete structure. The center bay is comprised of two 5 feet 3 inch long stoplog bays. The remaining 4 outer bays have a fixed crest. The spillway releases overflow and facilitates water level manipulation by adding or removing stoplogs. The stoplogs are held in place by steel channels imbedded within the concrete spillway. A steel frame and timber deck bridge allows vehicular and pedestrian traffic to cross the spillway. There was a bridge inspection done in October of 2021 and due to load rating standards the load rating was decreased to a maximum of 7 ton per axle and was posted accordingly.

Infrequent and undocumented water manipulations occurred early in the dam’s existence. A MDNR Dam Safety Inspection Report filed in 1995 mandated the repair and replacement of several stoplogs and other portions of the dam/bridge.

The draw-down required to facilitate these repairs provoked intensive investigation of the wetland complex. During the draw-down, many questions were posed regarding the impacts of Westman Dam upon the surrounding wetland complexes. MDNR personnel explored alternative management strategies, but due to a strong public opposition to the MDNR’s preference for permanent removal of the stoplogs, a more active management plan has been developed.

There are ongoing complaints from the public regarding this dam and its perceived impacts to water levels on the three upstream lakes. The public believes that the placement of stop logs has a direct impact on the water depth in the lakes. The complaints are typically regarding Hayward Lake, as this lake has a private hunt club and associated cabins. There is also a primitive boat launch on Hayward Lake that is unusable during low water years. Because of the perceived impact of the stop logs, periodically, private citizens put treated lumber into the stop log bays.

WILDLIFE MANAGEMENT GOALS

The MDNR Wildlife Division (WLD) will manage the dam to minimize negative impacts upon the Walton River system while maximizing any positive contributions that can be identified. Documented negative impacts of dams include warming of water temperatures, reduction of dissolved oxygen content, increased water depths above the dam, and creation of movement barriers. All these impacts can have unintended negative impacts upon fish and other aquatic organisms. Positive impacts of the dam may include creation of increased shallow-water habitat for local and migratory wildlife on the Walton River, and perhaps easier access to the north portion of North Lake for human recreationists.

MANAGEMENT TECHNIQUES

To reduce the negative impacts of the Westman Dam on the Walton River system and the northern portion of North Lake, stoplogs will be placed in the center bay(s) only during the late summer and fall period. This is the period when the local public was most adamant that stoplogs were needed and beneficial. Potential benefits include deeper water in the Walton River channel and increased marsh adjacent to the river for waterfowl hunting and furbearer trapping. The public believes the addition of stoplogs will also increase water depths in North and Hayward Lakes, thus improving boat access and creating better conditions for use of the area by waterfowl.

Stoplogs will be placed in the center bay(s) during August and September, and they will be removed during December. Stoplogs will be added at a rate such that a minimum downstream flow of 5 cubic feet per second is maintained in August and September, and 10 cubic feet per second is maintained in October.

Maximum stoplog height will be the same as the concrete top of the adjacent fixed-height spillways (approximately 7 10-inch wide stoplogs can be added to each of the 2 center bays so long as minimum downstream flows are maintained).

All stoplogs will be removed during the month of December at a rate not to exceed 1 row per day to prevent downstream flooding and erosion. This will serve to return water depths to normal levels in the river and the northern portion of North Lake during the winter, spring, and summer period. This action will reduce or eliminate the negative impacts of the dam on aquatic organisms during this period, and will improve conditions for the germination of wild rice within North Lake (a species that requires relatively low water levels), PERMIT REQUIRED FOR DAM OPERATION

Under the provisions of the Natural Resources and Environmental Protection Act 451, PA 1994 as amended, and specifically Part 301 Inland Lakes and Streams, a permit is required from the Michigan Department of Environmental Quality to install and remove stoplogs in the Westman Dam. On April 16, 2020 MDNR WLD was issued Permit No. WRP022017 to operate the Westman Dam in a manner specified in this plan. The Permit expires April 16, 2025.

INSPECTION SCHEDULE AND MAINTENANCE CHECKLIST

Maintenance inspections will be completed by WLD staff each spring and fall (prior to 30 June and 30 October, respectively). Michigan Department of Environment, Great Lakes, and Energy staff will inspect the dam every 5 years, following significant flood events, and/or, following any other special circumstances.

WLD staff will complete the following actions during inspections:

1. Remove brush, and debris from spillways and embankments.

2. Check stoplogs for flaws.

3. Replace stoplogs when necessary.

4. Inspect spillways for leaks.

5. Examine submerged portions of the spillway for wear during extended draw-down years.

6. Inspect the bridge for soundness and safety.

WLD staff will make carry out the following recommended actions:

1. Remove all trees and brush from the earthen embankments by the end of 2024. After clearing, mow both embankments a minimum of two times per year to prevent further establishment of woody vegetation and to facilitate visual inspection.

2. Repair minor spalling of the principal spillway pier noses and walls as soon as practical (likely 2023).

3. Periodically review the dam’s Operation and Maintenance Plan (O&M Plan) and update as necessary. Provide updated copies to the Dam Safety Program (completed on 02/22/2023).

WILDLIFE DIVISION CONTACTS

Wildlife Technician, Colter Lubben, Escanaba DNR Customer Service Center (telephone: 906-789-8204) Wildlife Biologist, Joe Sage, Escanaba DNR Customer Service Center (telephone: 906-789-8205)