WATERSHED CONDITIONS STATEMENT – Flood Outlook gives early notice of the potential for flooding based on weather forecasts calling for heavy rain, snow melt, high wind or other conditions that could lead to possible high runoff, riverine flooding, ice jams, lakeshore flooding, or erosion.
Water levels on local watercourses within NBMCA jurisdiction are generally at above-average levels for this time of year due to the relatively early start to the melt, but these levels are typical of spring freshet. Lake Nipissing and the Ottawa River remain low, as there has been limited snowmelt from northern areas yet this year. Weather forecasts for the next few days include an estimated 9mm of precipitation this (Wednesday) evening, and a further 7mm tomorrow (Thursday), with a large portion of it likely to fall as rain. The high temperature on Thursday will be around 7 ºC, with the lows staying slightly above zero around 1 ºC. Continued precipitation is forecast in the days following, with 3mm Friday, 5mm Saturday, and 2mm Sunday, but temperatures will cool with Saturday’s low forecast around -14 ºC.
While snowpack still remains across NBMCA jurisdiction (average snow-water equivalence of 89mm at NBMCA snow survey sites as of March 23rd), with the warm temperatures and rainfall so far this month the snowpack is now “ripe” and any additional rainfall will result in melting and runoff to area watercourses and waterbodies.
It is anticipated that urbanized watercourses within NBMCA jurisdiction, such as Chippewa Creek, will rise Thursday with the rainfall and warm temperatures. Ice has been removed from Parks Creek to help increase capacity and reduce high levels in that area. Rural watercourses will have a delayed response as rural watersheds take more time to accumulate runoff, but they are likely to rise later on Thursday and may continue to rise on Friday. In some areas rural watercourses remain elevated from the rainfall last weekend, and are expected to rise further with the additional rainfall forecast. It is expected that the cool weekend temperatures will slow the melt and runoff.
Localized flooding from area watercourses is possible if substantial rainfall and snowmelt occurs, and water is likely to accumulate on roadways, parking lots, and flat or low-lying areas. Serious flooding is not anticipated at this time.
All residents, especially those in low-lying areas, are encouraged to monitor the conditions that are developing. Municipalities are encouraged to monitor shorelines and water crossings, and respond to high water levels as necessary.
Banks adjacent to rivers and creeks become very slippery with precipitation, and when combined with open and/or fast-moving water can pose a serious hazard. The warm temperatures and rainfall is also likely to degrade ice conditions on lakes and other waterbodies, and appropriate caution is advised. Parents are encouraged to keep their children and pets away from watercourses and water bodies.
A close watch on local conditions and updated forecasts and warnings from Environment Canada is also recommended. Staff at the North Bay-Mattawa Conservation Authority will continue to monitor weather and watershed conditions and provide updates if conditions change.
The general public is advised of these messages through the www.nbmca.ca website with the flood status icon and a link to information about current conditions. NBMCA also circulates these messages to local media and social media, posting on Twitter (@theNBMCA), Instagram (nbmcainfo), and Facebook (theNBMCA).
The public is invited to share photos of watershed conditions on social media using #NBMCAFlood.
This message will be in effect until (or updated before) Monday, March 28, 4:00pm.
Terminology: Notification Levels
WATERSHED CONDITIONS STATEMENT: general notice of potential flooding or other conditions that pose a safety risk. There are two kinds of statements:
• Water Safety indicates that high flows, unsafe banks, melting ice or other factors could be dangerous for users such as anglers, boaters, swimmers, children or pets. Flooding is not expected.
• Flood Outlook gives early notice of the potential for flooding based on weather forecasts calling for heavy rain, snow melt, high wind or other conditions that could lead to high runoff, cause ice jams, lakeshore flooding or erosion.
FLOOD WATCH notifies that the potential for flooding exists within specific watercourses and municipalities. Municipalities, emergency services and individual landowners in flood-prone areas should prepare.
FLOOD WARNING: Flooding is imminent or already occurring in specific watercourses or municipalities. Municipalities and individuals should take action to deal with flood conditions. This may include road closures and evacuations.
Duty Officer: Kurtis Romanchuk C: (705) 498-1462 F: (705) 474-9793 email: email@example.com www.nbmca.ca