By BILL ZIEGLER
For The Daily News
CRYSTAL FALLS - Michigamme Reservoir located in east-central Iron County is approximately 7,000 surface acres.
The high stumps of old trees flooded by the Michigamme Reservoir are exposed during the drawdown. There is some flooded timber that can be just at the surface of the water and be a navigational hazard during open water boating. Care should be taken whenever boating this reservoir, especially if you're new to this water.
This reservoir impounds the Deer, Fence, and Michigamme Rivers as well as several smaller streams.
Michigamme Reservoir has been used for hydropower generation as well as water storage and release to facilitate eight of WE Energies downstream hydropower dams. The power dam was built in the late 1940s.
Its previous winter operation was to draw the water level down regularly and completely to a level 39 feet below full pool. At full drawdown the only remaining water was in the former small lake beds and old stream channels that had been inundated by the reservoir.
At full drawdown the impoundment had been reduced from about 7,000 acres down to about 700 acres.
Under old drawdown operations fish habitat was severely limited and impacted during the winter.
Aquatic vegetation and large wood cover were destroyed by the impact of the ice on the reservoir bottom. The drawdown also resulted in crowding of juvenile walleye and forage fish into a very limited area with an extreme seasonal density of predators (larger pike and walleyes). Additionally these juvenile game fish were crowded into a high density of predators with little or no natural cover.
The drawdown dewatering and ice also degraded invertebrate (aquatic insects, etc.) foods of the walleye.
DNR fisheries biologists in Crystal Falls documented a regular pattern where extremely large natural year classes (generations) of walleye were produced regularly by natural reproduction. Unfortunately, the large year classes had very poor over-winter survival which resulted in relatively low adult walleye populations at the reservoir.
The Wilderness Shores Agreement between WE Energies and the resource agencies (DNR, U.S. Fish and Wildlife Service etc.) provided for a compromise in the drawdown practices to benefit the fisheries.
As part of the new Federal Energy Regulatory Commission operating license for the Way Dam, the winter drawdown was limited to 15 feet (compared to the previous 25 to 39 foot winter drawdown).
This resulted in a low winter pool of about 3,700 acres rather than the previous 700 at full drawdown.
This also resulted in providing significantly more aquatic habitat to lessen the extreme concentration of juvenile with adult game fish (walleye and pike) that are both very cannibalistic.
The compromise premise was that lessening the drawdown would result in improved winter survival of walleye fingerlings, forage fish species and improved subsequent walleye populations. It was also hoped that higher winter pools will also result in improved aquatic vegetative cover for fish. The agreement also provides for a more modest summer drawdown.
There have been considerable DNR fisheries surveys done at Michigamme Reservoir prior to the change in hydro drawdown operations.
Population estimates were conducted on the walleye and northern pike in 1986 and 1987. These efforts indicated the walleye population was less than two adult walleye per acre, which is relatively low considering the consistent strong natural walleye reproduction.
Age and growth studies found slow growth rates for northern pike and walleye.
These results led to removing the minimum size limit on pike at this water. Although the overall pike size structure is poor, a small percentage of fast growing female pike grow through the growth bottleneck.
Michigamme Reservoir annually produces several trophy sized pike that are large enough to utilize the abundant sucker forage base there.
Annual fall walleye natural reproduction surveys were conducted which indicated that Michigamme Reservoir was successfully consistently producing a higher density of young-of-the-year walleye than any other water documented in the state.
As stated earlier the same surveys on age one walleye indicated that over winter survival was poor.
In anticipation of the upcoming change in drawdown operations a comprehensive walleye population survey was completed again in 2001.
This survey was to be used as a baseline to measure any progress gained after ten years by the compromise drawdown limits at the reservoir.
This survey found the same poor pike size structure found previously. Out of over 1,500 northern pike sampled only just over 5 percent of the pike were over the 24-inch state wide minimum size limit.
The walleye population survey indicated modest abundance for a large reservoir at 2.6 adult walleye per acre.
Initial fall walleye surveys following the drawdown modification indicated that over winter survival of walleye natural reproduction improved.
Unfortunately, these natural reproduction surveys were discontinued by the DNR in recent years. In addition, the follow up walleye population survey was not carried out as well, so the progress of the drawdown compromise cannot be definitively evaluated.
The change in winter drawdown did allow for Wildlife Unlimited of Iron County to construct several log crib reefs in the Deer River (west portion) arm of the reservoir.
Prior to the modified drawdown such habitat work would have futile since the ice would readily crush the cribs if they were placed where there would be effective habitat.
The crib reefs had to be placed so the 15 foot drawdown would not reach the crib tops although they had to be put shallow enough that fish would still use them in them in the summer.
The location of the reefs can be found on the Wildlife Unlimited of Iron County web site wluoic.org/. Anglers fishing the crib reefs since they have been completed have had success catching walleye, black crappie, bluegill and occasional pike.
Michigamme Reservoir gets quite a bit of angling pressure although it is spread out over this large impoundment.
Many local anglers have their favorite spots they have been open water or ice fishing for many years.
It is not like fishing a natural lake; the water levels are often gradually changing in both winter and summer.
Some areas that are good when the pool level is high are not very productive as the water level drops.
In the past during open water many walleye anglers use search methods like slow trolling and drifting to locate active walleye.
We have had success finding small wood cover on the bottom and finding fish around those features.
Early in open water walleye season some males can be found around the river and stream inlets.
The water is stained brown so jigs or spinner blades with bright colors like chartreuse or orange are always a good bet.
Bluegill and bass fishing have improved since the modified drawdown practices have been followed.
There is no hydrographic lake map publically available for Michigamme Reservoir.
Anglers with the higher tech electronic fish finders can obtain a map by ordering a lake map chip from Navionics online that include a depth map of Michigamme Reservoir.
With less good area walleye fishing opportunities in recent years, exploring and fishing Michigamme Reservoir is a good consideration.
In addition to public boat access sites spread throughout the reservoir it has several rustic camp grounds operated by WE Energies.
Free WE Energies maps titled "Welcome to Wilderness Shores" show the public access sites and camping areas.