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: 2026-04-20

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)
n/a
Graph View and Advanced Data

Grenville

Current Conditions

Water levels in metres
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Graph View and Advanced Data

Thurso

Current Conditions

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

Gatineau (Hull)

Current Conditions

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

Lake Coulonge at Fort-Coulonge

Current Conditions

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

Ottawa River at Carillon

Current Conditions

Water levels in metres
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Daily Flow (m3/s)
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Graph View and Advanced Data

Lake Deschenes at Britannia (Ottawa)

Current Conditions

Water levels in metres
n/a
Daily Flow (m3/s)
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Graph View and Advanced Data

Ottawa River at Chats Falls GS

Current Conditions

Water levels in metres
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Daily Flow (m3/s)
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Graph View and Advanced Data

Ottawa River at Chenaux GS

Current Conditions

Water levels in metres
n/a
Daily Flow (m3/s)
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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
n/a
Daily Flow (m3/s)
n/a
Graph View and Advanced Data

Mattawa

Current Conditions

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

Ottawa River at Otto Holden GS

Current Conditions

Water levels in metres
n/a
Daily Flow (m3/s)
n/a
Graph View and Advanced Data

River Levels and Flows

Water levels at 24:00h in metres 2026-04-13 2026-04-14 2026-04-15 2026-04-16 2026-04-17 2026-04-18 2026-04-19 2026-04-20
Otto Holden Generating Station Graph View and Advanced Data Agency: OPG 174.10 174.15 174.16 174.34 174.62 174.95 175.06 175.17
Mattawa Graph View and Advanced Data Agency: WSC 152.50 152.97 153.16 152.93 153.15 153.25 153.35 153.28
Des Joachims Generating Station Graph View and Advanced Data Agency: OPG 149.61 149.66 149.65 149.73 149.85 149.97 150.03 150.10
Pembroke Graph View and Advanced Data Agency: OPG 112.11 112.37 112.68 112.88 112.94 113.04 113.05 113.06
Lake Coulonge at Fort-Coulonge Graph View and Advanced Data Agency: HQ 106.69 106.90 107.31 107.73 108.08 108.34 108.42 108.49
Chenaux Generating Station Graph View and Advanced Data Agency: OPG 86.09 86.18 86.21 86.13 85.95 85.88 85.82 85.76
Chats Lake at Arnprior Graph View and Advanced Data Agency: OPG 74.50 74.65 74.86 75.09 75.35 75.54 75.59 75.64
Lake Deschenes at Britannia (Ottawa) Graph View and Advanced Data Agency: WSC 59.14 59.22 59.36 59.54 59.75 59.96 59.99 60.02
Gatineau (Hull) Graph View and Advanced Data Agency: HQ 42.76 43.07 43.31 43.53 43.76 43.98 44.05 44.11
Thurso Graph View and Advanced Data Agency: HQ 41.82 42.05 42.25 42.38 42.53 42.69 42.73 42.77
Grenville Graph View and Advanced Data Agency: HQ 41.42 41.60 41.76 41.85 41.94 42.07 42.12 42.14
Carillon Generating Station Graph View and Advanced Data Agency: HQ 40.51 40.51 40.52 40.51 40.50 40.50 40.51 40.51
Average Daily Flows (m3/s) 2026-04-13 2026-04-14 2026-04-15 2026-04-16 2026-04-17 2026-04-18 2026-04-19 2026-04-20
Ottawa River at Temiscaming Graph View and Advanced Data Agency: PSPC 870970106810801139119912921243
Ottawa River at Otto Holden GS Graph View and Advanced Data Agency: OPG 10031159129013231346139714971353
Des Joachims Graph View and Advanced Data Agency: OPG 14381871233624182317244125242591
Ottawa River at Chenaux GS Graph View and Advanced Data Agency: OPG 19542091239127393163350737963891
Ottawa River at Chats Falls GS Graph View and Advanced Data Agency: OPG 25222675299633793791421245704747
Lake Deschenes at Britannia (Ottawa) Graph View and Advanced Data Agency: WSC 24982639287331843572399643234390
Ottawa River at Carillon Graph View and Advanced Data Agency: HQ 45104955558059686343672371847036

River Conditions Forecast

Last Update: 2026-04-19 3:48 PM
Next Update: 2026-04-20 4:15 PM

Water levels and flows continue to rise at all locations along the main stem of the Ottawa River as significant runoff from rainfall and snowmelt from the unregulated portion of the basin flow into the river. Reservoirs are retaining spring runoff to reduce flooding in the dowstream river system. Minor flood levels have been exceeded in most flood prone areas along the Ottawa River from Pembroke down to Carillon. Major flood levels from Lake Coulonge to Carillon have been exceeded or are expected to be exceeded tomorrow or Tuesday. The minor and major flood levels are defined on the Home page in the Special Feature section. Levels should continue increasing over the next few days in all locations and start stabilizing on Monday. Our website Forecasts section provides expected water levels over a four-day horizon in several areas. Uncertain weather factors play into estimating peak levels over the coming week. On April 19 peak level estimates are generally above 2025 peak levels but below 2023 peak levels, as follows: Pembroke (113.10 m), Lac Coulonge (108.60 m), Chats Lake (75.70 m), Lake Deschenes (60.25 m), Gatineau -Hull marina (44.50 m) and Thurso (43.00 m). These exceed 2025 peak levels by 25 cm (Pembroke), 45 cm (Lake Coulonge), 45 cm (Chats Lake), 50 cm (Lake Deschenes/Britannia), 95 cm (Gatineau -Hull marina) and 70 cm (Thurso). Over the next two weeks, levels 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