LOW WATER LEVEL 1 CONDITION

Message Number: 2025-02

Issued: September 3, 2025 at 2:00 PM EDT

From: NBMCA Duty Officer, Angela Mills

Low Water Advisory – Level 1 Condition indicates that the received rainfall and/or streamflow in gauged watercourses are below normal and have met the Ministry of Natural Resources (MNR) criteria for low water. The Ontario Low Water Response program uses a three-tiered advisory system used to inform the public of local low water conditions where Level 1 is the least severe and Level 3 is the most severe. Level 1 is meant to be the first indication of a potential water supply issue. Voluntary water use reductions are encouraged.

Current Conditions:

Received rainfall at the North Bay Airport climate station for June, July, and August was a total of 270 mm this year, which is 95.6% of the long-term average (1991-2020) of 282 mm, however the total rainfall in August was 40.6 mm, which is just 43.6% of the long-term average (1991-2020) of 93.1 mm.

The 31-day average streamflow at the Chippewa Creek gauge is 0.170 m³/s, 61% of its lowest average summer month flow of 0.281 m³/s. The 31-day average streamflow at the La Vase River is currently 0.027 m³/s, 10% of its lowest average summer month flow of 0.275 m³/s. The water level at the gauge on the Wasi River has been impacted by beaver works and is not representative of local conditions. Both gauged water courses with reliable data meet the streamflow criteria to declare a Level 1 Low Water Condition (streamflow < 70% lowest average summer month flow).

Current water levels can be viewed by searching Station Names “Ottawa River”, “Mattawa River”, “Chippewa Creek”, “La Vase River”, “Wasi River”, and “Lake Nipissing” at https://wateroffice.ec.gc.ca/search/real_time_e.html

Though there are no criteria for water levels in the Ontario Low Water Response program, water levels on Lake Nipissing are low and declining per Public Services and Procurement Canada, a result of lack of precipitation in the area. The water level on Lake Nipissing is regulated by dams operated by the federal government. Current conditions are available at https://www.canada.ca/en/public-services-procurement/services/infrastructure-buildings/bridges-docks-dams/frenchriver-dam.html

Forecasted Conditions:

The 3-month seasonal forecast from Environment Canada indicates conditions for Fall 2025 are likely to be warmer and drier than normal. The 14-day forecast is projecting a possible 21-36 mm of rain, cumulatively through September 17. For the 3-month precipitation to not meet the criteria for low water conditions by the end of this month, September will need to be wetter than normal. It is likely that conditions will still meet the criteria for low-water conditions for the foreseeable future.

Historic Low Water Conditions:

For comparison, current streamflow conditions are slightly lower than those of the end of October 2024, when a Level 1 Low Water Condition was confirmed and extended through to January 2025. Other periods of low water where an advisory of Level 1 Low Water Conditions have been issued include: June to August 2021, August 2018, and August 2012. There have not been any confirmed Level 2 or Level 3 Conditions in the North Bay-Mattawa watershed.

Risk:

Level 1 Low Water status is the first indication of a potential water supply problem, based on the precipitation and streamflow criteria established by the Ministry of Natural Resources (MNR).

Due to the lack of rainfall and low water levels across the watershed, all residents are encouraged to voluntarily reduce their water consumption, targeting an overall water usage reduction of 10%.

The vulnerability of municipal water supply systems within the North Bay-Mattawa Conservation Authority (NBMCA) area of jurisdiction was assessed through a water budget stress assessment as part of the Drinking Water Source Protection program. All municipal water intakes within NBMCA jurisdiction were determined to have a low level of risk. Municipal water supply issues are not anticipated at this time. Private water systems were not assessed.

Low water levels mean that submerged hazards may be closer to the surface in some areas than in the past. Boaters are encouraged to exercise additional caution in areas with low water.

Staff at NBMCA will continue to monitor weather and watershed conditions and provide updates as conditions change.

The general public is advised of these messages through the www.nbmca.ca website with the low water 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).

This message will remain in effect until further notice.

Where a Conservation Authority has not been established, the MNR District Office is responsible for local Low Water Response programs. https://www.lioapplications.lrc.gov.on.ca/webapps/swmc/low-water-response/

Low water levels

The Low Water Response Program has three condition levels. The levels are based on trends in streamflow and rainfall.

LEVEL 1 CONDITION is the first indication of a potential water supply problem. A Water Response Team (WRT) may be convened. Voluntary water use reductions are encouraged, targeting an overall 10% reduction.

Level 1 is based on the following criteria:

18-month precipitation < 80% of average, or
3-month precipitation < 80% of average, or
Monthly flow < 80% lowest average summer month flow, or

In Spring (i.e., April, May, June) only:

Monthly flow < 100% lowest average summer month flow.

LEVEL 2 CONDITION indicates a potentially serious water supply problem. The WRT may contact individual water users and Permit To Take Water (PTTW) holders to encourage further water use reductions, targeting an overall 20% reduction.

Level 2 is based on the following criteria:

18-month precipitation < 60% of average, or
3-month precipitation < 60% of average, or
1-month precipitation < 60% of average, or
3 weeks with < 7.6mm rainfall, or
Monthly flow < 50% lowest average summer month flow, or

In Spring (i.e., April, May, June) only:

Monthly flow < 70% lowest average summer month flow.

LEVEL 3 CONDITION indicates the failure of the water supply to meet the demand, resulting in progressively more severe and widespread socioeconomic effects. The WRT may ask the province to impose mandatory restrictions on those holding Permits to Take Water.

Level 3 is based on the following criteria: