Ottawa RiverRegulationPlanning BoardCommission de planificationde la régularisationde la rivière des Outaouais

See the “River Conditions Forecast” message (Forecasts page) for details about flood risks. Read more

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Current Conditions

Publication: 2026-04-21

Snow Map

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

This map includes markers showing the location of gauges for which information on flows and water levels is available. This information is used for the integrated management of the principal reservoirs within the Ottawa River Basin.

For more information on the Terms of Use of this map, please visit the "About this map" section below.

Ottawa River at Temiscaming

Current Conditions

Daily Flow (m3/s)
(2026-04-21 00:00:00)
1528.67
Graph View and Advanced Data

Grenville

Current Conditions

Water levels in metres
(2026-04-21 00:00:00)
42.28
Graph View and Advanced Data

Thurso

Current Conditions

Water levels in metres
(2026-04-21 00:00:00)
42.97
Graph View and Advanced Data

Gatineau (Hull)

Current Conditions

Water levels in metres
(2026-04-21 00:00:00)
44.38
Graph View and Advanced Data

Lake Coulonge at Fort-Coulonge

Current Conditions

Water levels in metres
(2026-04-21 00:00:00)
108.63
Graph View and Advanced Data

Ottawa River at Carillon

Current Conditions

Water levels in metres
(2026-04-21 00:00:00)
40.51
Daily Flow (m3/s)
(2026-04-21 01:00:00)
7529
Graph View and Advanced Data

Lake Deschenes at Britannia (Ottawa)

Current Conditions

Water levels in metres
(2026-04-21 00:00:00)
60.18
Daily Flow (m3/s)
(2026-04-21 00:00:00)
4761
Graph View and Advanced Data

Ottawa River at Chats Falls GS

Current Conditions

Water levels in metres
(2026-04-21 00:00:00)
75.79
Daily Flow (m3/s)
(2026-04-21 01:00:00)
5037
Graph View and Advanced Data

Ottawa River at Chenaux GS

Current Conditions

Water levels in metres
(2026-04-21 00:00:00)
85.6
Daily Flow (m3/s)
(2026-04-21 01:00:00)
4065
Graph View and Advanced Data

Pembroke

Current Conditions

Water levels in metres
n/a
Graph View and Advanced Data

Des Joachims

Current Conditions

Water levels in metres
(2026-04-21 00:00:00)
150.26
Daily Flow (m3/s)
(2026-04-21 01:00:00)
2469
Graph View and Advanced Data

Mattawa

Current Conditions

Water levels in metres
(2026-04-21 00:00:00)
153.55
Graph View and Advanced Data

Ottawa River at Otto Holden GS

Current Conditions

Water levels in metres
(2026-04-21 00:00:00)
175.98
Daily Flow (m3/s)
(2026-04-21 01:00:00)
1684
Graph View and Advanced Data

River Levels and Flows

Water levels at 24:00h in metres 2026-04-14 2026-04-15 2026-04-16 2026-04-17 2026-04-18 2026-04-19 2026-04-20 2026-04-21
Otto Holden Generating Station Graph View and Advanced Data Agency: OPG 174.15 174.16 174.34 174.62 174.95 175.36 175.71 175.98
Mattawa Graph View and Advanced Data Agency: WSC 152.97 153.16 152.93 153.15 153.25 153.15 153.20 153.13
Des Joachims Generating Station Graph View and Advanced Data Agency: OPG 149.66 149.65 149.73 149.85 149.97 150.08 150.15 150.26
Pembroke Graph View and Advanced Data Agency: OPG 112.37 112.68 112.88 112.94 113.04 113.09 113.03 113.04
Lake Coulonge at Fort-Coulonge Graph View and Advanced Data Agency: HQ 106.90 107.31 107.73 108.08 108.34 108.55 108.61 108.63
Chenaux Generating Station Graph View and Advanced Data Agency: OPG 86.18 86.21 86.13 85.95 85.88 85.70 85.63 85.60
Chats Lake at Arnprior Graph View and Advanced Data Agency: OPG 74.65 74.86 75.09 75.35 75.54 75.70 75.75 75.79
Lake Deschenes at Britannia (Ottawa) Graph View and Advanced Data Agency: WSC 59.22 59.36 59.54 59.75 59.96 60.08 60.14 60.15
Gatineau (Hull) Graph View and Advanced Data Agency: HQ 43.07 43.31 43.53 43.76 43.98 44.19 44.29 44.38
Thurso Graph View and Advanced Data Agency: HQ 42.05 42.25 42.38 42.53 42.69 42.82 42.90 42.97
Grenville Graph View and Advanced Data Agency: HQ 41.60 41.76 41.85 41.94 42.07 42.17 42.23 42.28
Carillon Generating Station Graph View and Advanced Data Agency: HQ 40.51 40.52 40.51 40.50 40.50 40.50 40.51 40.51
Average Daily Flows (m3/s) 2026-04-14 2026-04-15 2026-04-16 2026-04-17 2026-04-18 2026-04-19 2026-04-20 2026-04-21
Ottawa River at Temiscaming Graph View and Advanced Data Agency: PSPC 9701060108011391199127914011490
Ottawa River at Otto Holden GS Graph View and Advanced Data Agency: OPG 11591290132313461397145214831686
Des Joachims Graph View and Advanced Data Agency: OPG 18712336241823172441254522642467
Ottawa River at Chenaux GS Graph View and Advanced Data Agency: OPG 20912391273931633507384640444065
Ottawa River at Chats Falls GS Graph View and Advanced Data Agency: OPG 26752996337937914212464349535030
Lake Deschenes at Britannia (Ottawa) Graph View and Advanced Data Agency: WSC 26392873318435723996438046694690
Ottawa River at Carillon Graph View and Advanced Data Agency: HQ 49555580596862606581709475517585

River Conditions Forecast

Last Update: 2026-04-20 4:41 PM
Next Update: 2026-04-21 4:15 PM

Spring runoff from the unregulated portion of the basin is currently at its highest, with northern reservoirs retaining a large portion of the spring runoff to reduce flooding in the downstream river system. Water levels and flows are expected to continue increasing from Mattawa to Pembroke over the next few days and are expected to start stabilizing today between Lake Coulonge and Lake Deschenes, and Wednesday between Gatineau-Hull and Carillon. Minor flood levels in Mattawa could be exceeded over the next few days, and have been exceeded from Pembroke down to Carillon. Major flood levels have been exceeded in flood prone areas from Lake Coulonge to Lake Deschenes, and are expected to be reached or exceeded today from Gatineau-Hull to Carillon. The minor and major flood levels are defined on the Home page in the Special Feature section. Downstream of Pembroke, water levels are expected to slowly increase until a peak is reached on Tuesday or Wednesday. Our website Forecasts section provides expected water levels over a four-day horizon in several areas. On April 20 peak level estimates are close to 2023 peak levels, as follows: Pembroke (113.20 m), Lake Coulonge (108.75 m), Chats Lake (75.85 m), Lake Deschenes (60.30 m), Gatineau -Hull marina (44.70 m) and Thurso (43.10 m). These are lower than the 2023 peak levels by 10 cm (Pembroke), 0 cm (Lake Coulonge), 5 cm (Chats Lake), 5 cm (Lake Deschenes/Britannia), 0 cm (Gatineau -Hull marina) and 10 cm (Thurso). Over the next two weeks, levels from Lake Coulonge to Carillon are expected to plateau or slowly decline depending on weather. Risk of further increase in levels over coming weeks is higher from Mattawa to Lake Coulonge given the high snowpack remaining in the northern part of the basin.

View Four-day Forecasts

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, or when the flow is zero m3/s.  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, or flow of zero m3/s