Ottawa RiverRegulationPlanning BoardCommission de planificationde la régularisationde la rivière des Outaouais

INCREASING FLOOD RISK ALONG THE OTTAWA RIVER (Mattawa to the Montreal Region). See the River Conditions Forecast message that is updated daily. Read more

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Current Conditions

Publication: 2025-04-30

Snow Map

Locations to display: River locations only | Reservoirs only | Other locations

Ottawa River at Temiscaming

Current Conditions

Daily Outflow (m3/s)
(2025-04-30 05:00:00)
2068.6
Graph View and Advanced Data

Grenville

Current Conditions

Water levels in metres
(2025-04-30 07:00:00)
41.63
Graph View and Advanced Data

Thurso

Current Conditions

Water levels in metres
(2025-04-30 07:00:00)
42.13
Graph View and Advanced Data

Gatineau (Hull)

Current Conditions

Water levels in metres
(2025-04-30 07:00:00)
43.36
Graph View and Advanced Data

Lake Coulonge at Fort-Coulonge

Current Conditions

Water levels in metres
(2025-04-30 07:00:00)
108
Graph View and Advanced Data

Ottawa River at Carillon

Current Conditions

Water levels in metres
(2025-04-30 07:00:00)
40.49
Daily Outflow (m3/s)
(2025-04-30 07:00:00)
5239
Graph View and Advanced Data

Lake Deschenes at Britannia (Ottawa)

Current Conditions

Water levels in metres
(2025-04-30 06:00:00)
59.7
Daily Outflow (m3/s)
(2025-04-30 06:00:00)
3680
Graph View and Advanced Data

Ottawa River at Chats Falls GS

Current Conditions

Water levels in metres
(2025-04-30 07:00:00)
75.17
Daily Outflow (m3/s)
(2025-04-30 07:00:00)
3683
Graph View and Advanced Data

Ottawa River at Chenaux GS

Current Conditions

Water levels in metres
(2025-04-30 07:00:00)
85.9
Daily Outflow (m3/s)
(2025-04-30 07:00:00)
3300
Graph View and Advanced Data

Pembroke

Current Conditions

Water levels in metres
(2025-04-30 04:00:00)
112.81
Graph View and Advanced Data

Des Joachims

Current Conditions

Water levels in metres
(2025-04-30 07:00:00)
150.24
Daily Outflow (m3/s)
(2025-04-30 07:00:00)
2643
Graph View and Advanced Data

Mattawa

Current Conditions

Water levels in metres
(2025-04-30 06:00:00)
153.82
Graph View and Advanced Data

Ottawa River at Otto Holden GS

Current Conditions

Water levels in metres
(2025-04-30 07:00:00)
175.03
Daily Outflow (m3/s)
(2025-04-30 07:00:00)
2069
Graph View and Advanced Data

River Levels and Flows

Water levels at 24:00h in metres2025-04-232025-04-242025-04-252025-04-262025-04-272025-04-282025-04-292025-04-30
Otto Holden Generating StationGraph View and Advanced Data Agency: OPG174.10174.11174.19174.34174.54174.74174.84175.03
MattawaGraph View and Advanced Data Agency: WSC152.82153.02153.16153.21153.43153.64153.57153.82
Des Joachims Generating StationGraph View and Advanced Data Agency: OPG149.52149.56149.53149.64149.79149.95150.02150.24
PembrokeGraph View and Advanced Data Agency: OPG112.36112.40112.46112.60112.71112.77112.76112.81
Lake Coulonge at Fort-CoulongeGraph View and Advanced Data Agency: HQ107.07107.18107.26107.40107.61107.82107.88108.00
Chenaux Generating StationGraph View and Advanced Data Agency: OPG86.1386.1186.0886.0886.1086.0386.0585.90
Chats Lake at ArnpriorGraph View and Advanced Data Agency: OPG74.6774.7474.8074.8474.9475.0775.0875.17
Lake Deschenes at Britannia (Ottawa)Graph View and Advanced Data Agency: WSC59.2659.3259.3659.4259.4659.5559.6159.70
Gatineau (Hull)Graph View and Advanced Data Agency: HQ42.6142.6942.7742.8342.9243.1043.1743.36
ThursoGraph View and Advanced Data Agency: HQ41.6341.6941.7541.7841.8441.9542.0042.13
GrenvilleGraph View and Advanced Data Agency: HQ41.2841.3141.3441.3841.4241.5041.5341.63
Carillon Generating StationGraph View and Advanced Data Agency: HQ40.5340.5140.5140.5040.5040.5140.5140.49
Average Daily Outflow (m3/s)2025-04-232025-04-242025-04-252025-04-262025-04-272025-04-282025-04-292025-04-30
Ottawa River at TemiscamingGraph View and Advanced Data Agency: PSPC13321404153017121775181919682069
Ottawa River at Otto Holden GSGraph View and Advanced Data Agency: OPG14391489159617611828187320212069
Des JoachimsGraph View and Advanced Data Agency: OPG18161900205522252415241224252643
Ottawa River at Chenaux GSGraph View and Advanced Data Agency: OPG21772304241025092684294831913300
Ottawa River at Chats Falls GSGraph View and Advanced Data Agency: OPG27712878298630823176335635863683
Lake Deschenes at Britannia (Ottawa)Graph View and Advanced Data Agency: WSC27642852296330743167327834313680
Ottawa River at CarillonGraph View and Advanced Data Agency: HQ42084267435644844639481551545239

River Conditions Forecast

Last Update: 2025-04-29 4:28 PM
Next Update: 2025-04-30 4:30 PM

Flows and water levels on the main stem of the Ottawa River continue to rise due to increased runoff from ongoing rainfall combined with snowmelt from the mountainous areas of the basin. Minor flood levels have been reached in Pembroke, Lake Coulonge and Britannia, and should be reached in Mattawa and Chats Lake on Thursday. Levels may reach or exceed the major flood level from Lake Coulonge to Lake Deschenes depending on the rapidity of snowmelt and precipitation amount received today. From Gatineau (Hull Marina) down to the Montreal Region, levels are expected to exceed minor flood levels but should remain below major flood levels. Our website Forecasts section provides expected water levels over a four-day horizon in your area. Levels are expected to peak starting Thursday-Friday between Lake Coulonge and Lake Deschenes, and starting Saturday from Gatineau down to the Montreal Region. Uncertain weather factors play into estimating peak levels. On April 29 peak level estimates are: Pembroke (113.15 m), Lac Coulonge (108.40 m), Chats Lake (75.45 m), Lake Deschenes (60.05 m), Gatineau -Hull marina (44.00 m) and Thurso (42.60 m).

View complete forecast

Additional content

About this map

This map includes markers representing the location of gauges where information on flows and water levels are available. Data collected at gauges shown on the ‘River locations only’ and ‘Reservoirs only’ maps is used for the integrated management of the principal reservoirs within the Ottawa River Basin.

Instruction:

The coloured markers on this map depict conditions (level or flow) as a range of conditions categorized in three groups:  for normal conditions,  for above normal,  for below normal. The marker is  when the current day’s value or percentile are not available.  On the ‘River locations only’ map, the colour of the markers for locations with run-of-river facilities is based on flow conditions.  On the ‘Reservoirs only’ map, the marker colour for all locations is based on the water level in the reservoir.

Click on any marker to see the most recent data from this location and what type of data is measured there. To view data related to the principal reservoirs in the basin, select ‘Reservoirs only’ in the upper right corner. Near real-time and historical data is available for additional locations by selecting ‘Graph View and Advanced Data’. Water levels at 24:00 means at midnight.

Terms of Use:

The data provided by this web service may not be reproduced or redistributed.  Contact the Ottawa River Regulation Secretariat  for information on how to obtain historical data directly from the data owner.

Users of the flow data, water level data, and hydrological forecasts shown on this website must recognize that such information is considered preliminary data.  Users must therefore accept that the information provided carries an unspecified level of uncertainty and are advised to be cautious if they intend to use the information for decision-making.  Please see the Disclaimer for further details.

The flow rates and actual levels can change rapidly without warning, particularly during the freshet period. We advise those using bodies of water to exercise caution and to always follow established safety guidelines when near water.

Understanding Range of Conditions:

The three ranges are based on percentiles, which are computed from the observations of the current day of the year over a period of 30 years (1991-2020). The percentile (P) is the percent of all data that is lower than the actual value for the current day of the year.

: Normal conditions, between P10% and P90%

: Above normal conditions, P is equal or greater than P90%

: Below normal conditions, P is lower than P10%

: Current day value or percentile not available