Manicouagan Reservoir

Manicouagan dam (at left) and spillway (in the middle)

Photo.

Photo: N. Chartrand

A. LOCATION

Quebec, Canada.
50:8N, 68:3W; ca. 366 m above sea level.

B. DESCRIPTION

Manicouagan Reservoir is on the Canadian Shield which is Precambrian in origin and similar in type to the Scandinavian Shield. It covers more than 90% of the province and is located north of the St. Lawrence River. This region is characterized by a disorganized collection of the hills with rounded peaks rarely more than 1,500 m high. The depressions between the hills are frequently occupied by lakes and rivers. This is why, depending on the sector, 20 to 50% of the region's surface is occupied by aquatic habitats. In this region, we find all of the major reservoirs built by Hydro-Quebec (e. g. the La Grande Project Area near James Bay).
The Manicouagan Reservoir is the most important reservoir of the Manicouagan Hydroelectric Complex. This reservoir is the result of the impoundment of two arched lakes (Manicouagan and Mouchalagan) and rivers. When the impoundment was completed, the reservoir took a final circle form with an island in the middle (Ile Rene-Levasseur). This circle form and the pattern of the local topography is the result of the impact of a meteorite which changed the nature of the rocks and affected the geological structure. The water of the reservoir is poor in mineral or organic elements and lightly acid. The water is as clear as all nordic lakes and has a low productivity. Situated at approximately 220 kilometers south of the reservoir, Baie-Comeau is the regional centre of this part of the North Shore (Q).

C. PHYSICAL DIMENSIONS (Q)

Surface area [km2]	1,950
Volume [km3]	141.6
Maximum depth [m]	350
Mean depth [m]	85
Water level	Regulated
Normal range of annual water
level fluctuation [m]	5.6, 19.8*
Length of shoreline [km]	1,322
Residence time [yr]	8
Catchment area [km2]	29,241

D. PHYSIOGRAPHIC FEATURES

D1 GEOGRAPHICAL
Sketch map: Fig. NAM-26-0l.
Names of main islands: Ile Rene-Levasseur.
Number of outflowing rivers and channels (name): 1 (Manicouagan R.).
D2 CLIMATIC
Climatic data at Manic 5*, November 1975-January 1988 (l)
Mean temp. [deg C]

Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Ann.
-23	-	-	-	-	-	14	-	-	-	-	-	-3

Precipitation [mm]

Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Ann.

-	-	-	-	-	-	-	-	-	-	-	-	600

Number of hours of bright sunshine: 1,990 hr yr-1.
Solar radiation (Iles A)[MJ m-2 day-1](2)


Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Ann.

4.32	8.04	11.78	14.86	18.36	20.6	18.47	17.05	11.69	7.14	4.13	3.16	11.6

Water temperature [deg C]
Station 1, 1972
[m]


Depth	Jun	Jul	Aug

S*	-	8-14	-

Six stations, 1985
[m]


Depth	Jun	Jul	Aug

S	2.7-3.4	-	11.0-16.0
2	2.9-3.5	-	12.0-14.6
10	2.9-3.3	-	9.5-14.5
B*	2.9-4.5	-	4.0-5.5

Freezing period: September-early June.
Mixing type: Monomictic.
Notes on water mixing and thermocline formation
The thermocline was located between 6 and 7 m in June of 1985 in one basin which was protected from the wind by high banks. In another one near the centre of the lake, the thermocline was located between 10 and 15 m.

E. LAKE WATER QUALITY

E1 TRANSPARENCY [m]
Six stations, June and August 1985
[m]


Depth	Jun	Aug

	6.5òÐ67	4.9òÐ67

E2 pH
Six stations, June and August 1985
[m]


Depth	Jun	Aug

S*1	6.10-6.46	5.20-6.50
2	6.17-6.45	6.12-6.47
10	6.12-6.45	6.10-6.49
B*2	6.00-6.50	6.02-6.37

E4 DO [mg l-1]
Six stations, August 1985
[m]


Depth	Aug

S*1	10.3-11.9
2	10.3-12.3
10	9.9-12.1
B*2	10.0-12.2

E7 NITROGEN CONCENTRATION (3)
NO3-N [mg l-1]
Six stations, June and August 1985
[m]


Depth	Jun	Aug

S*1	0.40-0.42	0.17-0.26
2	0.42-0.52	0.18-0.45
10	0.42-0.80	0.15-0.42
B*2	0.42-0.66	0.40-0.52

E8 PHOSPHORUS CONCENTRATION (3)
PO4-P [mg l-1]
June and August 1985
[m]


Depth	Jun	Aug

S*1	<0.05	<0.05
2	<0.05	<0.05
10	<0.05	<0.05
B*2	<0.05	<0.05

E9 CHLORIDE CONCENTRATION [mg l-1](3)
Six stations, June and August 1985
[m]


Depth	Jun	Aug

S*1	0.13-0.24	0.16-0.26
2	0.16-0.22	0.14-0.17
10	0.16-0.25	0.14-0.22
B*2	0.16-0.22	0.14-0.18

F. BIOLOGICAL FEATURES (Q)

1972

F1 FLORA
Phytoplankton
Dominant taxa: Anabaena sp., Glenodinium pulvisculus and Peridinium sp. (4). Chrysophyta (Dinobryon divergens, D. bavaricum, D. sertularia, D. cylindricum, D. vanhoeffenii, Mallomonas unaformis), Bacillariophyta (Asterionella formosa, Ceratoneis arcus, Cyclotella stalligera, Melosira granulata, Rhizosolenia eriensis, Stephanodiscus binderanus, Synedra rumpens, Tabellaria fenestrata, T. flocculosa), Chlorophyta (Ankistrodesmus sp., Arthrodesmus sp., Dictyosphaerium pulchellum, Gloecystis sp., Microspora pachyderma, Mougeotia sp., Oocystis sp., Staurastrum sp.).

F2 FAUNA
Zooplankton (4)
Zooplankton quality and quantity (no m-3), for May, June and July, 1972


Stations	M-1		M-2		M-3		M-4		M-5
Dates	10/5	10/7	9/5	19/6	17/5	14/7	17/5	14/7	17/5

Cladocerans			*
Holopedium gibberum								34
Holopedium sp.
Daphnia longiremis
	95		42	10	6	117	20	84	150
Daphnia catawba								6
Bosmina longispina						11	20	12
Bosmina sp.		6
Polyphemus pediculus								6
Sida crystallina
Total	95		48	10	6	128	40	142	150
Copepods
Diaptomus minutus	36		36		6	54	10	130	20
Diaptomus sanguineus				5
Diaptomus sp.	5				5
Epischura lacustris						64		17
Epischura sp.
Cyclops scutifer		1	12	15		190	2	280	3
Cyclops capillatus						2
Cyclops vernalis
Cyclops bicuspidatus lubbocki									3
Cyclops sp.	843					72
Total	884	1	48	20	83	308	14	417	26
Immatures
Cladocerans	53
Copepods	964	3	222	250	60	1105	200	792	1960
	M-6		M-7		M-8		M-9	M-10		M-11
	17/5	14/7	17/5	14/7	13/7	12/7	17/5	12/7	17/5	>11/7
Cladocerans
Holopedium gibberum		63				11
Holopedium sp.					2	2
Daphnia longiremis
	50	280	30	150	192	188	120	713	10	69
Daphnia catawba
Bosmina longispina
	2	107	20	95	132	82	2	32	2
Bosmina sp.										5
Polyphemus pediculus						2
Sida crystallina				12
Total	52	450	50	257	326	285	122	745	12	74
Copepods
Diaptomus minutus 20	630	40	320		4		21
Diaptomus sanguineus	50	135	11
Diaptomus sp.		2		2					10
Epischura lacustris				75	11	24
Epischura sp.	114
Cyclops scutifer	10	430	2	565	2		41	2	100	48
Cyclops capillatus	140
Cyclops vernalis							16
Cyclops bicuspidatus lubbocki
Cyclops sp.					2
	Total	32	1214	44	960	15	75	52	156	160	59
Immatures
Cladocerans			24		55		250
Copepods	1020	3040	970	2083	354	397	950	652	80	554

Rotifers (July 1972): Asplanchna, Conochilus, Euchlanis, Filinia, Gastropus,
Kellicottia, Monstyla, Polyarthra, Synchaeta, Trichocerca.
Fish
Information not available because the commercial fishing started last year as a new project. Whitefish was the principal species caught (4,500-5,440 kg) in 1987.

G. SOCIO-ECONOMIC CONDITIONS

G1 LAND USE IN THE CATCHMENT AREA
1987*
Types of important forest or scrub vegetation
A mixed forest with Abies balsamea, Picea mariana, Betula papyrifera, Populus tremuloides, and Pinus divaricata.
Main kinds of crops and/or cropping systems
There are no field crops in this region; wildlife (e. g. moose, caribou, lynx) are harvested through sport hunting and trapping.
*Comments on land use refer only to the shoreline and not to the watershed as a whole.

G3 POPULATION IN THE CATCHMENT AREA
1986: Total 506 max. No information for whole catchment area.

H. LAKE UTILIZATION

H1 LAKE UTILIZATION
Recreation (sport-fishing), fisheries (a project was started in 1987 (1)) and others (outfitting, cottages on public lands and traditional uses of the land and lake by native people).

H2 THE LAKE AS WATER RESOURCES
1986


	Use rate [m3 sec-1]

Power plant	580*

I. DETERIORATION OF LAKE ENVIRONMENT AND HAZARDS

I1 ENHANCED SILTATION
Extent of damage: Not serious.
Supplementary notes
During the reservoir filling stages, the erosion of till, rock, sand, cobbles, pebbles and blocks on the shorelines caused an increase in the concentration of suspended solids and enhanced the rates of mineralization. This stimulated primary productivity in the reservoir once the level of suspended solids had settled permitting better light penetration through the water column of the reservoir.

I2 TOXIC CONTAMINATION
Present status: Detected but not serious.
Supplementary notes
Significant levels of mercury were detected in fish which is normal for reservoirs in this type of terraine and geological setting.
Main contaminants, their concentrations and sources in 1985

Name of Range of concentration [ppm]*1 Main sources
contaminant Fish*2

Mercury           Whitefish         0.217-0.772
                  Northern pike     0.4-2.37
                  Long nose sucker 0.241-0.433      Geological
                  White sucker      0.17-0.61

*1 Wet weight basis.
*2 The mercury level in the fish refers to the standards
fillet.

> Food safety standards or tolerance limits for toxic
contamination residue
For mercury, the commercial level is 0.5 ppm for the fish.

J. WASTEWATER TREATMENTS (Q)

J1 GENERATION OF POLLUTANTS IN THE CATCHMENT AREA
(a) Pristine lake environments.

L. DEVELOPMENT PLANS (Q)

No development plans apart from permitting logging, cottage
development and
fishing and hunting outfitters will be permitted to establish
bases in the
area.

M. LEGISLATIVE AND INSTITUTIONAL MEASURES FOR UPGRADING LAKE
ENVIRONMENTS (Q)

M1 NATIONAL AND LOCAL LAWS CONCERNED
> Names of the laws (the year of legislation)
(1) Loi sur la qualite de l'environnement, L. R. Q., c. Q-2
> Responsible authorities
(1) Government of Quebec
> Main items of control
(1) All kinds of pollution

M2 INSTITUTIONAL MEASURES
(1) Ministere du Loisir, de la Chasse et de la Peche (Quebec),
Ministere de
l'Environnement (Quebec), Environment Canada

N. SOURCES OF DATA

Questionnaire filled by Dr. N. Chartrand, Manager,Environmental Research and Public Health, Environment Branch, Hydro-Quebec,Montreal.
Demers, C. D. The Importance of Geographical Aspects in Environmental Studies of Hydro-Quebec Reservoirs. Montreal, Quebec.
Canadian Climate Normals (1951-1980) Environment Canada,Atmospheric Environment Service.
Jones H. G. & Onge, J. S. (1985) InventairePhysico-Chemique et Ichtyologique des Eaux du Reservoir Manicouagan 5 (Quebec).
Jones, G., Leclerck, M., Meybeck, M., Quellet, M. &Rousseau,A. (1973) Etude Limnologique Preminaire du Reservoir Manicouagan,Quebec. Univ. du Quebec, INRS-Eau, Quebec.