By Greg Price
Barnwell village council is taking a wait-and-and-see approach to how fast the village is growing before acting upon a raw water supply and storage study it was issued by MPE Engineering at its Sept. 15 meeting.
The objective of the report was to provide the Village of Barnwell with a review of current and projected raw water demands to ensure adequate supply is available to meet anticipated growth.
Population projections for the report were determined using Statistics Canada census data, where it was determined the growth rate of four per cent per year be used for projections. The four per cent growth rate in the report is in line with historical averages for Barnwell from 2001-2011. Prior to 2006, growth in the village was steady with the census population remaining unchanged from 2006 to 2011. Village council will decide how to act on the storage study once it receives the data from the 2016 Census which will be available Feb. 8, 2017.
“It’s very much dependent on population projections. You might see the village growing,” said Andrew Kleisinger, environmental systems manager at MPE Engineering. “You’ve seen a rapid growth in Barnwell and you saw that in the water plant last summer in reaching capacity in the plant which led to our expansion project.”
If the four per cent population increase projection continues forward, Kleisinger noted there will be an issue involving raw water supply.
“Four per cent is a very aggressive growth rate and talking with Wendy (Bateman, CAO for the Village of Barnwell), the last year or two years, that has somewhat leveled off,” said Kleisinger. “Say if you look at a more reasonable growth rate like two per cent, that shifts the window of really needing to do something from imminent to 20 years down the road. The population is key to this whole study. That led us to the recommendation of let’s sit back until the Census 2016 data is available. Then you can re-evaluate these options at that time.”
The Village of Barnwell is currently authorized to divert 200,000 cubic metres of raw water annually from the Taber Irrigation District canal for the purpose of Municipal Urban Water Supply. The village is also supplied with up to 72,737 cubic metres of raw water per year through an agreement with the Town of Taber. The current available raw water supply will exceed projected raw water demands by 2028 according to the MPE report.
Since the Village of Barnwell can only divert raw water from the TID canal during the irrigation season between May and September, the non-irrigation season (October to April) is the most critical time for raw water supply. Currently, the village can store up to 37,000 cubic metres of raw water in raw water storage reservoirs adjacent to the water treatment plant. The village is permitted to withdraw 72,737 cubic metres from the Taber-Chin raw water pipeline during the non-irrigation season and only during periods when the Town of Taber is operating their raw water supply pumps. As a result, during non-irrigation season, the available raw water volume is 109,737 cubic metres. Based on this volume, the Village of Barnwell can sustain its raw water demands in the non-irrigation season until 2025.
“Obtaining additional allocation is really not an option. This basin is closed to new allocation so Alberta Environment won’t really consider that,” said Kleisinger. “Your only option for getting more water allocation is talk to another licence holder in the area and get allocation from them.”
In the MPE report five different options based on the aggressive four per cent population increase yearly was factored in which would see Barnwell turn into a town with a population of 2,165 in 2036. Doing no upgrades would mean Barnwell’s available raw water supply will last until 2025. Rejected water recycling, increasing raw water storage, and re-purposing the abandoned reservoir adjacent to the Taber Pipeline Pump Station were all given as options for extending the sustainability of the current available raw water.
“We went out to look at it. There would be a lot involved in sort of refurbishing that (abandoned reservoir) location to get it up to the point where it would be useful,” said Kleisinger. “It is also a very shallow reservoir where you would possibly be introducing more water-quality issues that the plant might not be able to handle. Being quite shallow, it’s susceptible to algae blooms, not to mention the political side of it between the TID and the town and everyone involved. That one is not really a tangible option.”
If the population growth ends up being half of the aggressive four per cent projection, Kleisinger re-emphasized that the urgency for raw water supply/storage expansion becomes noticeably lessened.
“Is four per cent realistic? If it is two per cent per year, which is still fairly significant growth, it extends the timely period by like 20 years. There’s really no need to do anything until 2048 based on a two per cent growth rate,” said Kleisinger.