Low Water Status
Above average winter rainfall moves Conservation Halton Watershed from Level I Low Water Condition to Normal
Based on precipitation figures for the last three months and current stream levels, Conservation Halton is updating the Low Water Status within our watershed from Level I Low Water Condition back to a Normal Condition. Above average temperatures through December and January has resulted in more precipitation falling as rain which has aided the recovery of local streamflow.
Streamflows for the month of January were compared to the lowest recorded summer average flows at a number of long-term gauging stations within the Conservation Halton watershed and found to be over 300% greater, and are now within the limits defined as ‘Normal’. As noted, a significant factor in the recovery of streamflow was the average temperature in January being more than 3.0°C warmer than normal which resulted in much of the recorded precipitation falling as rain instead of snow. Environment Canada data recorded average air temperatures of -1.0°C and -2.1°C in January 2017 compared to long-term averages of -4.7°C and -5.5°C observed at Hamilton Royal Botanical Gardens and Hamilton Airport respectively. As a result, accumulated snowpack within the watershed has also melted causing runoff in local creeks and streams to increase.
Precipitation totals from November 2016 to January 2017 (three months) at select gauging stations within the Conservation Halton watershed were compared to long-term averages over the same period and also showed a marked increase back to Normal conditions. In fact, from late December to present, portions of the watershed have received nearly 200% of the average amount of precipitation normally recorded over this duration, which when combined with average precipitation totals observed from the start of December, has significantly influenced the transition back to Normal conditions.
“This has not been a typical winter to-date. The fluctuations in air temperature and warmer than normal conditions experienced over the last several months has resulted in higher amounts of precipitation falling as rain instead of snow. Resultant runoff has increased stream levels which has aided in a return to a Normal Condition status. However, the observed variations in weather has significantly increased monitoring activities carried out by our Flood Forecasting and Operations staff compared to previous years,” said Janelle Weppler, Associate Director of Engineering. To illustrate this statement, Conservation Halton has issued three Water Safety messages since the start of this winter.
Conservation Halton (CH) declared a Level I Low Water Condition on July 8, 2016 and, subsequently declared a Level II Low Water Condition on August 8 as the month of July continued to yield warm and dry conditions across the region. The last time Conservation Halton had declared a Level II Low Water Condition for its watershed was August 20, 2007. While August brought a return of normal to above normal precipitation, it was not enough to counteract the dry conditions from April through July. However, due to increases in streamflow from reservoir releases, conditions warranted an improvement to Level I at the end of October.
Low Water Conditions
Conservation Halton, in partnership with the Ministry of Natural Resources and Forestry, assists in the co-ordination and support of local response in the event of a drought. We monitor local water level and precipitation closely and work with local water users to reduce demand and mitigate effects of water shortages, encouraging voluntary water conservation measures. Consisting of representatives from the Province, Municipalities, Conservation Authorities, local water users and interest groups, a Water Response Team is coordinated by Conservation Halton in its watershed.
There are three levels of Low Water Conditions:
|•||Normal||Conditions are within normal limits.|
|•||Level I||First indication of potential water supply problems, primarily a warning level - Key focus is on voluntary conservation of water|
|•||Level II||Indicates a potentially serious problem - conservation of water is extended to restrictions on non-essential uses|
Indicates a failure of the water supply to meet demand - Key focus is on conservation, regulation and enforcement of non-essential uses
The Plan identifies three categories of water usage that would be used in ranking water usage allocation under Level 3 low water conditions as follows:
- Essential Uses consist of water uses which deal with human life and health; a reasonable supply of water for drinking and sanitation, health care and public institutions (wastewater treatment, fire protection, schools and power generation) as well as water required for basic ecological functions
- Important Uses consist of uses important for social and economic well being and would include activities critical to industry, commercial operations and agriculture
- Non Essential Uses consist of uses which can be interrupted for a short period without significant impact and would include private swimming pools, lawn watering, public and private fountains and vehicle washing