01 Department of Agriculture, Conservation and Forestry


Table 3 Kennebec River - Principal Tributaries



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Table 3
Kennebec River - Principal Tributaries



Tributary

Drainage Area

(square miles)

Length

(miles)

Fall

(feet)

Moose River


722

76

750


Dead River

874

23

570

Carrabasset River

401

35

636

Sandy River

596

69

1544

Sebasticook River

946

48

270

Flagstaff Reservoir, another large regulated lake, is located in the Dead River tributary watershed. The Carrabassett and Sandy Rivers are hydrologically flashy, draining unregulated mountainous terrain, whereas the Sebasticook River drains flatter, more hydrologically sluggish, terrain.4


FISH AND WILDLIFE HABITAT
Nontidal Mainstem Waters.
The East Outlet flows for 2.6 miles between Moosehead Lake and Indian Pond. It provides spawning, nursery, and adult habitat for coldwater game fish species. Because of the gradient (average drop of about 25 feet per mile), the channel configuration, and the substrate, the river is comprised of riffles and rapids throughout much of its length. When provided with a flow adequate to wet the entire natural stream channel, it contains nearly 275,000 square yards of excellent nursery habitat for salmon. As there are very few gravel areas, suitable salmon and trout spawning habitat is limited. Several deep pools and runs provide cover and serve as resting habitat for adult salmonids.
Flows in the East Outlet are controlled by the dam at the outlet of Moosehead Lake. Normal mean monthly flows range between 1,400 and 3,900 cubic feet per second. A minimum flow of 200 cubic feet per second is required by the present FERC license for the Moosehead Project, and minimum flows occur most often in late winter. This minimum flow is not adequate to cover the entire river bottom from bank to bank across the natural channel. Higher than normal flows are normally associated with spring runoff, and occur after Moosehead Lake has filled. Maximum flows which exceed 10,000 cubic feet per second have also been discharged at other times of the year after major storm events that occurred when Moosehead Lake was full.

Although the West Outlet is longer than the East Outlet (approximately 8 miles in length), it is a much smaller stream with less gradient. Two shallow ponds (Long Pond - 173 acres, Round Pond - 40 acres) and several deadwater areas are located along its course, with short sections of rocky riffles interspersed between longer, slow-moving sections.


Flows in the West Outlet are also controlled by the dam on Moosehead Lake. A minimum flow of 25 cubic feet per second is required by the present FERC license for the Moosehead Project, but historically the required minimum flow has been exceeded . Flows have averaged close to 80 cubic feet per second throughout much of the year, except when Moosehead Lake is drawn down in late winter. During periods of peak runoff, when Moosehead Lake is full, higher-than-normal flows are occasionally discharged through the dam. Several tributary streams enter the West Outlet downstream from Long Pond. Their natural flows augment water discharged into the West Outlet through the dam at Moosehead Lake.
Harris Dam to the Forks. The twelve mile long reach of river from Harris Dam to the Forks is characterized by a steep gradient and fluctuating water flows. The river drops about 355 ft. from Indian Pond, the impoundment formed by Harris Dam, to The Forks. Water flows are regulated at the Harris Dam to provide electric power during hours of peak demand. Consequently, daily flows vary widely. A reconnaissance survey conducted by IF&W in 1983 showed that the minimum flow of 140 cubic feet per second (cfs) results in the loss of otherwise available fish habitat through streambed dewatering. At Carry Brook, about 40-50% of the river bed was dewatered and at Fish Pond outlet where the river is wider, about 75% was dewatered.
High flows used for power generation as well as for whitewater rafting are thought to conflict with fisheries needs within this reach. Peak generating flows occur rather abruptly, raising water levels at the base of Harris Dam as much as 8 ft. in less than 10 seconds. The resulting flow velocities have not been quantified but they are thought to reduce the fishery potential in this reach by reducing the amount of useable coldwater fish habitat during high flow periods.
The combination of high flows and difficult access limits fishing opportunity. However, anglers who adjust to the release schedule at Harris Dam catch landlocked salmon and brook trout. Sporadic catches of rainbow trout have also been reported in the lower end of the reach. Most fish are from natural reproduction but some are fish which are dropped from stockings in Indian Pond and elsewhere in the drainage.
The Forks to Wyman Dam. The 8+/- mile long river section from The Forks to the upstream limit of the Wyman Lake, the impoundment formed by Wyman Dam, is almost continuous riffle. Pools are few and the stream bed is predominantly cobble. The section is subject to daily flow fluctuations from regulation at Harris Dam on the Kennebec and from Flagstaff Dam on the Dead River, a major tributary which enters the Kennebec at the Forks.
Wyman Lake covers 3240 acres at normal elevation. The impoundment, which averages about 0.5 miles wide, extends 14.4 miles upstream, just above the confluence of Pleasant Pond Steam and Pierce Pond Stream. The lake is unusual in that the thermocline, the narrow layer of cool, well oxygenated water lying between the warm surface layer and cold bottom layer, is located at 80 ft. Normally, the thermocline is located nearer the surface. The deep thermocline is thought to be caused by drawing water for power generation at Wyman Dam from a depth of 50 ft. and from the large volume of warm inflowing water from the Kennebec. The deep thermocline reduces but does not eliminate coldwater fish habitat.
Wyman Lake has both a winter and summer fishery for salmon, lake trout, pickerel, and smelts. There is also a spring dip net fishery for smelts at the upper end of the lake. Anglers report catching salmon, rainbow trout, and brook trout in the flowing water section. Fishing is not uniform throughout the section. Rather, anglers tend to concentrate at several specific areas.
The coldwater fish species in the fishery are from direct lake stocking and from natural reproduction occurring within the reach as well as from upstream waters. Unauthorized stockings of small mouthed bass and white perch in upstream waters will eventually establish themselves in this river reach with unpredictable results. Fishing in Wyman Lake may improve as a result but an overall reduction in the coldwater fishery is expected.
Wyman Dam, Moscow to Williams Dam, Solon. The mainstem of the Kennebec River from Williams Dam in Solon to Wyman Dam in Moscow is 8.4 miles long. The lower 4.2 miles of this reach are impounded by Williams Dam. When full, this impoundment is 426 acres in size; however, water levels normally fluctuate 5-7 feet/day as a result of upstream discharges from Wyman Dam. These discharges range from 490 cfs to 6,240 cfs. Wyman's maximum generating flow is 8,500 cfs. Average depths of the Williams impoundment vary from about 15 feet 1/3 mile above the dam to about 3 feet near the upper limit of the impoundment. Despite the depths in the lower section, the water quality is more riverine than lacustrine due to the high flushing rate.
The entire section supports coldwater sports fisheries for rainbow trout, brook trout, landlocked salmon, and to a lesser extent, lake trout and round whitefish. Other fish species present include brown trout, chain pickerel, yellow perch, rainbow smelt, suckers, sunfish, and minnows. Smallmouth bass and white perch, which are present upstream, can be expected to eventually migrate downstream. All of these species are self-sustaining. Rainbow trout were introduced above Solon in 1933, and were stocked by IF&W as recently as 1979. This species spawns during the early spring in several tributaries to the mainstem of the river, including Jackson Brook, Joe Foss Brook and Austin Stream. The other salmonids are fall spawners. Lake trout and landlocked salmon, better adapted to lacustrine than riverine habitat, grow slowly. Reduced length limits are therefore in effect for these species. No stocking is currently being done in this river section, though there may be escapement from private hatcheries near the river.
Although angling occurs throughout this section, the most popular sites include the tailrace below Wyman Dam, the gravel bar at the mouth of Austin Stream, the Cool Farm site (approximately 3.5 miles below Wyman Dam), and trolling is popular between Wyman Dam tailrace and the Route 16 bridge in Bingham. In a 1987 IF&W creel survey, 59% of the angling activity occurred during the months of May and June. Samples from that survey indicated that legal landlocked salmon and rainbow trout were II to IV years old; legal brook trout ages ranged from II to III.
A study conducted as part of the Wyman Dam relicensing evaluation concluded that fish populations below the dam are adversely affected by fluctuating flows. Negotiations to alter the flow regime or to provide mitigation are underway.
Solon Dam to Augusta Dam. Water flows in this section are controlled to a large extent by KWPC. KWPC attempts to operate upstream reservoirs to provide an average annual regulated flow of at least 3600 cfs at Madison. At Solon Dam, a near constant flow of 3200 cfs is passed. Inflows from the Carrabassett River and other smaller tributaries increase the flow to 3600 cfs at Madison when water is available. Dams at Madison-Anson operate run of the river providing stable flows to Skowhegan dam, with additional inflow from the Sandy River.
The 14 +/- miles long river section from Solon Dam to Madison-Anson contains both coldwater and warmwater fish habitat. Most of the coldwater fish habitat is in the 8 mile long reach from Solon Dam to the upstream limit of the impoundment formed by Anson Dam. It is riffle and pool type with gravel-cobble substrate. The 5.9 mile long impoundment is riverine in nature, better suited to warmwater fish species, with only seasonal coldwater fish habitat.
The 14 mile long river section from Madison to Skowhegan Dam is mostly impoundment formed by Weston Dam. The 12.5 mile long impoundment covers about 930 acres at full pond elevation. Average width is 620 ft. and it is riverine in character. The upstream limit of the impoundment is about 4000 ft. upstream from the confluence of the Sandy River.
Guides and anglers report catching brook trout, landlocked salmon, brown trout, and smallmouthed bass. All species reproduce naturally. Only brown trout are stocked at the present time but in the past all of the above named coldwater fish species have been stocked. There may also be escapement of rainbow trout and salmon into this section of the Kennebec River from private hatcheries located in the towns of Bingham and Embden. There is also a winter fishery, mainly for pickerel, in the Weston Island area. Most of the coldwater fish species between Madison and Skowhegan are caught in the 1.5 miles of flowing water between Abenaki Dam in Madison and the upstream limit of the Weston impoundment.
The area below the Solon/Embden bridge is considered to be excellent wildlife habitat. The Embden side of the river has high value as wildlife habitat.
The segment from Madison to Anson contains some of the most fragile riverine ecosystems in this corridor. The Savage to Weston island sector of the river in the middle of this segment is one of the most valuable wildlife areas in the river corridor.5
Near Skowhegan there is a considerable amount of wildlife habitat from Oak Islands to Hinckley Reach.6



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