PROVINCIAL LOW WATER LEVELS CONDITIONS REPORT

PROVINCIAL LOW WATER LEVELS CONDITIONS REPORT

Update for October 21, 2003

Region	Precipitation (monthly)¹		Flows (monthly)²
MNR Southern (previously referred to as Southcentral)	To date (Oct 23, 2003), watersheds in 12 Conservation Authorities (CA) are in a confirmed Low Water condition - 11 CAs have watersheds in Level I³only: (Ausable Bayfield, Kawartha Region, Kettle Creek, Long Point Region, Lower Thames Valley, Nottawasaga Valley, Otonabee Region, St. Claire Region, Quinte, Upper Thames Region, Grand River); and 1 CA has watersheds in Level II: (Catfish Creek) Most stations reported greater than 70% of the average precipitation for the third week of October¹ (By the end of the third week, 70% of the average precipitation for October would indicate a trend toward the average for the month). Southwestern Ontario reported a concentration of stations with precipitation below 70%. As of October 23, the Provincial Response Centre is forecasting 30 to 45 mm of precipitation over the next 5 days with the possibility of an additional 20-40 mm in localised showers.		Next update October 31 Flood Potential: Immediate flood threat is currently low, however, there is potential for the region to receive up to 85 mm of rain over the next 5 days.
	Average Historical Precipitation Overall average October precipitation ranges from 35mm to 110mm Most stations range from 60mm to 90mm Environment Canada Fall Outlook (September-October-November)⁵ Above normal precipitation for the eastern most portion of S. Ontario, normal elsewhere. Near normal temperatures for all of southern Ontario.
MNR Northeast	Most stations reported below 70% of the average precipitation expected for the third week of October¹(By the end of the third week, 70% of the average precipitation for October would indicate a trend toward the average for the month) Northeastern Ontario is forecast to receive 13 to 23 mm of rain over the next 5 days, with the possibility of an additional 5-8 mm in localised precipitation.	Next update October 31 Flood Potential: Immediate flood threat is currently low. Long term flood threat would be from widespread significant rainfall.
	Average Historical Precipitation Ranges from 75mm to 105 mm for October for most stations Environment Canada Fall Outlook (September-October-November) ⁵ Above normal precipitation Below normal temperatures
MNR Northwest	One MNR District is in a confirmed Level I low water condition: Dryden All but two stations reported below 70% of the average precipitation expected for the third week of October¹. (By the end of the third week, 70% of the average precipitation for October would indicate a trend toward the average for the month) Northwestern Ontario is forecast to receive 8 to 20 mm of rain over the next 5 days with the possibility of an additional 3-5 mm in localised precipitation.	Next update October 31 Flood Potential: Immediate flood threat is currently low. Long term flood threat would be from widespread significant rainfall.
	Average Historical Precipitation Ranges from 45 mm to 70 mm for October for most stations. Environment Canada Fall Outlook (September-October-November) ⁵ Above normal precipitation Below normal temperatures

^{1Environment Canada’s synoptic stations are equipped to measure snow. Precipitation gauges from dataloggers often are not set up to measure snow adequately. The resulting errors plus the elimination of many of the readings for these gauges means our precipitation coverage is poor during months with snow.

²For each gauge used in the analysis the average flow is calculated for July, and August and September from the historical record. The minimum of these three values is compared to the past month’s average flow. During the winter months most streams are partially filled or covered over with ice. This ice reduces the cross-section of the stream resulting in flow readings that are higher than actual. This error is corrected in the historical record. Thus the observed, relative to the historical minimum, is also higher than the actual in streams with significant ice conditions.

³ Level I conditions initiate the formation of a Water Response Team (WRT) which encourages a voluntary 10% reduction in water use. At Level II the WRT encourages a further 10% reduction by restricting non-essential water use; level III represents the condition where there is insufficient supply of water to meet all needs which July result in regulation of water use.

4Great Lakes summary includes information from Environment Canada, Great Lakes - St. Lawrence Regulation Office and the Detroit District U.S. Army Corps of Engineers.

5Outlook provided by Environment Canada. Environment Canada has assigned very low confidence to this season’s precipitation Outlook across the province and medium confidence to the temperature Outlook.

Val von Zuben
Surface Water Monitoring Officer
October 23, 2003}