Forecasts
Publication: 2025-04-03 4:15 PM
This map includes markers representing the locations where the Ottawa River Regulating Committee provides hydrological forecasts to the public. During the spring freshet, forecasts are updated Monday to Friday (and weekends when conditions may change rapidly).
Forecast Values
| Location | Type of value |
2025-04-03 (Forecast) |
2025-04-04 (Forecast) |
2025-04-05 (Forecast) |
2025-04-06 (Forecast) |
|---|---|---|---|---|---|
| Ottawa River at Temiscaming Graph View | Flow (m3/s) | 875 | 875 | 875 | 899 |
| Ottawa River at Mattawa Graph View | Level (m) | 151.80 | 151.80 | 151.80 | 151.85 |
| Ottawa River at Pembroke Graph View | Level (m) | 111.90 | 111.90 | 111.90 | 111.95 |
| Lake Coulonge at Fort-Coulonge Graph View | Level (m) | 106.45 | 106.45 | 106.50 | 106.50 |
| Chats Lake at Arnprior Graph View | Level (m) | 74.20 | 74.30 | 74.40 | 74.50 |
| Lake Deschenes at Britannia Graph View | Level (m) | 58.95 | 59.00 | 59.10 | 59.15 |
| Flow (m3/s) | 2200 | 2300 | 2450 | 2580 | |
| Ottawa River at Gatineau (Hull) Graph View | Level (m) | 42.55 | 42.70 | 42.80 | 42.90 |
| Ottawa River at Thurso Graph View | Level (m) | 41.65 | 41.75 | 41.80 | 41.85 |
| Ottawa River at Carillon Graph View | Flow (m3/s) | 4400 | 4800 | 5000 | 5200 |
River Conditions Forecast
Last Update: 2025-04-03 4:05 PM
Next Update: 2025-04-04 4:00 PM
Spring runoff is increasing in the southern part of the basin due to recent precipitation and ongoing warm temperatures. Levels and flows on the main stem of the Ottawa River are starting to increase in some locations as a result. With additional precipitation expected this weekend, water levels and flows are expected to increase gradually over the next few days from Chats Lake down to the Montreal area, but they should remain within their seasonal range. Rapid rise of levels and flows is possible in some locations depending on the speed of snowmelt and amount of rainfall received. Minor flooding in low-lying areas may occur over the coming week. Low-lying areas (such as recreational trails near water) are those locations that regularly flood during the spring freshet period.
Instruction:
During the spring freshet period, you may click on any marker to see additional information for this location and to access a Graph View of the data. Graph View is also accessible by clicking on any location in the table below.
- Level forecasts correspond to predicted level at the end of the day (11:59pm) on the specified date.
- Discharge forecasts correspond to predicted average daily discharges for specified dates.
- Note that water levels are measured in metres above mean sea level.
- The water levels forecasts do not account for local variations due to WIND and WAVES effects.
Please read the important warning below.
To find out how the Ottawa River Regulating Committee communicates important hydrological information about the Ottawa River to responsible provincial authorities, please click here.
Warning:
- These forecasts are prepared by the Ottawa River Regulating Committee to inform the collaborative management of principal reservoirs within the Ottawa River basin. These forecasts are used by provincial and federal government responsible authorities to assess flood risks. Only these authorities are responsible for disseminating forecasts to the public.
- These forecasts are based on the anticipated effect of reservoir regulation and on hydrological forecasting of natural inflows for a given weather forecast.
- Absolute accuracy of weather forecasts cannot be guaranteed. In addition, there are inherent uncertainties in the hydrologic models used to estimate inflows and the measurements of water levels and flows at various locations.
- The degree of uncertainty of these forecasts increases with the length of the forecasting horizon.
- Except in unusual circumstances, the table is updated in the afternoon and only on business days.
- 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.
- 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.