Controlling the flow

The website of the Ottawa River Regulation Planning Board, established in 1983 by the governments of Canada, Quebec, and Ontario to oversee the management of reservoirs of the Ottawa River basin, reports the daily water levels at various points along the Ottawa and the Gatineau Rivers, mentioning that, at present, "levels and flows on the main stem of the Ottawa River are slightly above normal for this time of the year." It also records the outflow from the Carillon dam in cubic metres per second (1700 at the last count).

The people most likely to be interested in these figures are the producers of hydro electric power in our region and the people vulnerable to floods. If there's too much or too little water flowing, one or the other of those groups is going to be affected.

Chelsea dam, Gatineau River

The dams on the Ottawa River and its tributaries are the places where the flow is controlled and the hydro electricity generated.

The combined capacity of the hydro-electric generating stations in the watershed is over 4000 MW, producing over $1 million worth of energy on a daily basis.

There are hundreds of dams and not all their effects are benefits. The Ottawa Riverkeepers list a few problems caused by dams:

• Blocking upstream and downstream migration of fish and mussels, thereby preventing them from reaching spawning and feeding areas
• Flooding, erosion, habitat washout
• Scouring and armoring of the riverbed by infrequent and large releases of water
• Rapid fluctuations in flow that do not mimic the natural flow patterns in rivers
• Modification of water-quality parameters including water temperatures, nutrient concentration and dissolved oxygen.