Guelph Outdoor Water Use Program
As of July 8 2016, southern Ontario has had no shortage of heat and a big shortage of rain. It seems that most days in the past month have had humidex values near or above 30°C, whereas precipitation over the last 3 months is less than half of the average. These conditions don’t coincide nicely at all with my formerly full-time landscaping job and complete lack of A/C, but I digress. In response to these conditions, the City of Guelph has upgraded from a level 1 to a level 2 on its Outside Water Use Program (OWUP). I don’t really know much about these advisories, so I’m going to take the opportunity to learn all about them and share it here for you.
Level 0: Careful Use
The default level where there is really only 1 guideline of any significance,
- Alternate day lawn watering (even vs odd house number), and only between the hours of 7AM-9AM and 7PM-9PM.
There are various other common sense guidelines, such as don't let your hose run the whole time you wash your car. There are no consequences for failure to adhere to these guidelines though. Instead, an educational approach is taken. This level exists when there are no significant hydrological abnormalities in the watershed.
Level 1: Reduce Outside Use
At level 1, nothing changes except that the guidelines become enforced rules. Failure to comply can result in $130 ticket or court summons for each incident of non-compliance. This level comes into effect when any of 3 conditions are met,
- No precipitation for 2 weeks, or less than 80% of historical average over 1 and/or 3 months
- Eramosa river flow is less than 70% of minimum low flow
- Water storage level is less than 75% of average
Unfortunately, there is no readily available definition of what ‘minimum low flow’ or ‘water storage level’ is. I am guessing that the minimum low flow reflects the amount of flow that is necessary to maintain healthy river conditions from an ecological standpoint, and I am guessing water storage level is just the water level at various dams throughout the city. I have reached out to the city for clarification and will update when they respond.
Level 2: Reduce and stop nonessential use
At level 2 the penalties for non-compliance remain the same as level 1, but the rules become much more restrictive,
- No lawn watering is permitted
- Decorative gardens can only be watered alternate days (even vs odd house numbers), and only between the hours of 7AM-9AM and 7PM-9PM.
- Vehicles may not be washed at home
The criteria for instating this level are,
- No precipitation for 3 weeks, or less than 60% of historical average over 1 and/or 3 month
- Eramosa river flow is less than 50% of minimum low flow
- Water storage level is less than 65% of average
Purpose of Limits and Effectiveness
Guelph relies almost exclusively on groundwater for it’s municipal water services. The groundwater in this region is a renewable resource, but it can be depleted during times of drought and/or through over-exploitation. This program is in place to avoid any short-term reductions in groundwater levels, while also encouraging long-term sustainability. It should be noted that during my research I didn’t encounter anything to suggest that the city’s water supply is currently significantly at risk. It seems to me that the city is simply opting for a proactive approach when it comes to sustainable water use.
The city website claims that 97% of residents abide by the rules and guidelines of this program, and that it has reduced Guelph’s average daily summer water use by 18 million liters. Given that the daily water use recently has been around 50 million liters, that is a remarkable claim. I would be interested in seeing how these numbers were determined, but the big picture results are abundantly clear; The city’s population grew by 12% since 2003, but daily drinking water production actually decreased by 13% through the same period. This is almost certainly thanks to programs like this.