PROVINCIAL LOW WATER LEVELS CONDITIONS REPORT

PROVINCIAL LOW WATER LEVELS CONDITIONS REPORT

Update for July 21, 2003

Region	Precipitation (monthly)¹		Flows (monthly)²
MNR Southcentral	To date (July 23, 2003), watersheds in 7 Conservation Authorities (CA) are in a confirmed Low Water condition - 5 CA’s are in Level I³: (Kettle Creek, Quinte, Saugeen Valley, Grand River, Ausable Bayfield); and 2 CAs have watersheds in Level II: (Catfish Creek, Grand River) Most stations reported below 70% of the average precipitation in the third week of July¹.* (By the end of the third week, 70% of the average precipitation for July would indicate a trend toward the average for the month). *Some portions of the southcentral region received additional rainfall from the 21^st to the 23^rd. This will be reflected in the month-end report. As of July 23, the Provincial Response Centre is forecasting 5 to 11 mm of rain over the next 5 days, with potential additional amounts falling locally.		Next update July 31 Flood Potential: Immediate flood threat is currently low. Long term flood threat would be from widespread and extensive rainfall.
	Average Historical Precipitation Overall average July precipitation ranges from 55mm to 100mm Most stations range from 75mm to 90mm Environment Canada Summer Outlook (June-July-August)⁵ Below normal precipitation near the lower Great Lakes and St. Lawrence River, normal elsewhere. Near normal temperatures for all of southern Ontario.
MNR Northeast	Most stations reported above 70% of the average precipitation expected in the third week of July¹ (By the end of the third week, 70% of the average precipitation for July would indicate a trend toward the average for the month). Northeastern Ontario is forecast to receive 5 to 13 mm of rain over the next 5 days.	Next update July 31 Flood Potential: Immediate flood threat is currently low. Long term flood threat would be from widespread and extensive rainfall.
	Average Historical Precipitation Ranges from 85 mm to 105 mm for July for most stations Environment Canada Spring Outlook (June-July-August) ⁵ Above normal precipitation Near normal temperatures
MNR Northwest	Two MNR Districts are in a confirmed Level I low water condition: Dryden and Kenora Most stations reported above 70% of the average precipitation expected in the third week of July¹ (By the end of the third week, 70% of the average precipitation for July would indicate a trend toward the average for the month). Northwestern Ontario is forecast to receive 4 to 11 mm of rain over the next 5 days with potential additional amounts falling locally.	Next update July 31 Flood Potential: Immediate flood threat is currently low. Long term flood threat would be from widespread and extensive rainfall.
	Average Historical Precipitation Ranges from 85 mm to 120 mm for July for most stations Environment Canada Spring Outlook (June-July-August) ⁵ Near normal precipitation for most of northwestern Ontario, except above normal in the far north Near normal temperatures for all of northwestern Ontario

^{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 and temperature Outlook across the province.

Valerie von Zuben
Surface Water Monitoring Intern

July 23, 2003}