On July 9, 2019 the Mississippi Valley Conservation Authority (MVCA) hosted a public information meeting at the Northwind Wireless Centre. The set up of the room was such that capacity was limited to about 150 people; the room was filled. The session was organized by the MVCA and attended by the community, Eli, City Staff, MVCA, ORRS, OPG, Merrillee, and media. A link to the presentation delivered by MVCA are below, the complementary slides delivered by Ottawa River Regulation Secretariat (ORRS/ORRPB) and OPG are not included in the package; we have requested them.

You will find below the links to the:

MVCA 2019-07-09 Info Meeting 

ORRPB 2019-06-22-Pembroke Public Meeting

Joachims backwater Ottawa-River-Graph-Freshet-2019-Final-May-10

ORRPB 2017_Spring_Flood_Summary

The following is a selection of Questions and ORRS Answers from the July 9^th meeting;

• How does the management of the St Lawrence River’s Moses-Saunders Dam in Cornwall effect Ottawa River management? “Plan 2014”, implemented in December 2016, governs the International Lake Ontario-St. Lawrence River Board which manages the flow through the Moses-Saunders Dam. The international board is required to monitor the Ottawa River forecasts for the Carillon Dam, issued by the ORRPB, and adjust accordingly to prevent flooding in Montreal. As a result, in the spring there is frequently an inverse relationship between the Carillon & Moses-Saunders flow rates so that an increase at Carillon causes a decrease at Moses-Saunders and a decrease at Carillon causes an increase at Moses-Saunders. ORRPB is not required to take the St Lawrence water levels into consideration while managing the Ottawa River Freshet.
• Why are some parts of the Ottawa low or dry while others flood? This is referred to as the “Joachims backwater effect” by OPG. The effect is required to prevent flooding in some communities. The condition occurs because there are natural obstructions along some stretches of the river where the outflow capacity exceeds the inflow capacity. See link above for a picture.
• What determines the water level in Constance Bay? This stretch of the river is called Lac Deschenes; the level is determined by the in-flow from Chats Falls GS and the run-off from the ground and adjoining creeks. There is no man-made obstruction at Brittania, which is at the end of Lac Deschenes. Water is held in Lac Deschenes by the rocks which form the Deschenes rapids; the Chaudiere Falls GS is many meters lower than Deschenes rapids and has no influence over the water level in Constance Bay.

• Levels in Lac Deschenes appeared normal/average before the Freshet; why was it not lowered further/sooner to prepare for this Spring? Answer was not provided but has been re-requested.

The following Question was answered by MPP Fullerton at the July 9^th meeting;

• Will there be an independent inquiry of the 2019 flood? An announcement is imminent. It was noted that this answer was also provided by MPP Yakabuski on June 22.