Publication: 2021-04-10Snow Map
Snow Water Equivalent
The map of the snow water equivalent can be found by clicking here.
This map gives an overview, at the time of measurements, of the amount of water held in the snow cover compared to the amount of water it normally holds at this same time of year. The map covers the entire Ottawa River watershed. At a glance, it is possible to see if there is more or less snow than usual.
It is important to note that the amount of water in the snow cover is only one of several factors that can influence the magnitude of the spring freshet. For more information on the factors that contribute to flooding, please consult our Frequently Asked Questions.
This map is updated approximately every two weeks in the period before and during the spring freshet.
Please note that recent snowfalls or thaws that have caused an increase in snow cover or melting of part of the snow cover may not have been represented in the map. Therefore, the conditions shown on the map may not perfectly reflect current field conditions.
To reference this map, please use ‘Ministère de l’Environnement et de la Lutte contre les changements climatiques, 2021. Data from the Réseau de surveillance du climat du Québec, Direction de la qualité de l’air et du climat, Québec.’
River Levels and Flows
|Water levels at 24:00h in metres||2021-04-03||2021-04-04||2021-04-05||2021-04-06||2021-04-07||2021-04-08||2021-04-09||2021-04-10|
|Otto Holden Generating Station Graph View and Advanced Data Agency: OPG||176.18||176.29||176.36||176.39||176.71||176.86||177.04||177.13|
|Mattawa Graph View and Advanced Data Agency: WSC||151.45||151.47||151.57||151.64||151.36||151.16||151.72||151.86|
|Des Joachims Generating Station Graph View and Advanced Data Agency: OPG||150.73||150.82||150.94||150.81||151.02||151.06||151.48||151.77|
|Pembroke Graph View and Advanced Data Agency: OPG||111.78||111.68||111.62||111.63||111.64||111.50||111.31||111.29|
|Lake Coulonge at Fort-Coulonge Graph View and Advanced Data Agency: HQ||106.43||106.30||106.18||106.22||106.20||106.19||106.21||106.21|
|Chenaux Generating Station Graph View and Advanced Data Agency: OPG||86.05||85.86||85.77||85.65||86.01||86.23||85.95||85.98|
|Chats Lake at Arnprior Graph View and Advanced Data Agency: OPG||74.20||74.16||74.04||74.01||74.14||74.11||74.07||74.12|
|Lake Deschenes at Britannia (Ottawa) Graph View and Advanced Data Agency: WSC||58.94||58.90||58.86||58.72||58.53||58.51||58.45||58.26|
|Gatineau (Hull) Graph View and Advanced Data Agency: HQ||42.18||42.18||42.11||41.95||41.79||41.77||41.74||41.59|
|Thurso Graph View and Advanced Data Agency: HQ||41.55||41.58||41.56||41.49||41.40||41.40||41.41||41.34|
|Grenville Graph View and Advanced Data Agency: HQ||41.34||41.41||41.40||41.36||41.30||41.32||41.33||41.28|
|Carillon Generating Station Graph View and Advanced Data Agency: HQ||40.80||40.97||41.04||41.04||41.05||41.09||41.11||41.11|
|Average Daily Outflow (m3/s)||2021-04-03||2021-04-04||2021-04-05||2021-04-06||2021-04-07||2021-04-08||2021-04-09||2021-04-10|
|Ottawa River at Temiscaming Graph View and Advanced Data Agency: PSPC||440||394||384||379||410||271||233||–|
|Ottawa River at Otto Holden GS Graph View and Advanced Data Agency: OPG||488||442||442||445||347||255||241||263|
|Des Joachims Graph View and Advanced Data Agency: OPG||786||677||648||841||538||419||461||526|
|Ottawa River at Chenaux GS Graph View and Advanced Data Agency: OPG||1658||1561||1407||1274||1192||1219||1046||952|
|Ottawa River at Chats Falls GS Graph View and Advanced Data Agency: OPG||2085||2061||1954||1645||1398||1553||1286||1199|
|Lake Deschenes at Britannia (Ottawa) Graph View and Advanced Data Agency: WSC||2223||2147||2073||1850||1549||1484||1421||1150|
|Ottawa River at Carillon Graph View and Advanced Data Agency: HQ||3588||3328||3289||3070||2668||2400||2330||1910|
River Conditions Forecast
Water levels and flows continue to slowly recede in most areas along the Ottawa River. With forecasts of above-normal temperatures over the next few days, the remaining snow in the northern parts of the basin is expected to continue melting over the next week. Most of the spring runoff from these northern areas will be stored in reservoirs in that part of the basin as principal reservoirs are being managed to reach their target summer levels. The general trend, for the full length of the river, is for a steady decrease in flows and levels as the remaining spring runoff in the central part of the basin recedes. Note: refer to the April 6 bulletin by the Ottawa River Secretariat regarding daily forecasting of river conditions no longer being required.
About this map
This map includes markers representing the location of gauges where information on flows and water levels are available. These are used for the integrated management of the principal reservoirs within the Ottawa River Basin and are also of interest to basin residents.
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.
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.
The data provided by this web service may not be reproduced or redistributed. Contact the Ottawa River Regulation Secretariat (see Contact us) for information on how to obtain historical data directly from the data owner.
Users of flow data and water level data shown on this website are cautioned to consider the unverified nature of the information before using it for decisions making. Please see the Disclaimer for further details.
The flow rate 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 follow safety rules at all times.
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 the last 30 years. 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 P25% and P75%
: Above normal conditions, P is equal or greater than P75%
: Below normal conditions, P is lower than P25%
: Current day value or percentile not available