NOTE: The numbers, data and findings highlighted in this article reflect information from a first-draft report. It is important to note that such information can and most likely will change over time.
OUTLOOK - A draft report from Associated Engineering studying the Town of Outlook's raw water supply has shed some light on the direction that the community's waterworks may be headed in the future.
The firm was tasked with completing the study in order to assess several options for supplying raw water to the town.
The report shares that in recent years, the small subchannel in the South Saskatchewan River where Outlook's raw water intake (RWI) is located experienced periods where it became partially cut off from the river, said to be due to active sand beds in that area of the water. This limited the flow towards the existing fish screen that's mounted at the mouth of the RWI. It further states that in 2019, the subchannel found itself completely isolated from the river, forcing the Town to rely on a temporary pumping mechanism that supplied water from the main river body into the subchannel where the RWI was located.
Associated Engineering worked with the Town on an application to the Investing in Canada Infrastructure Program (ICIP) in March of 2020, preparing a Class 'D' cost estimate for a new intake option as recommended by a report by Northwest Hydraulic Consultants.
The Town of Outlook was able to secure a maximum of $5.4 million in grant funding, targeted towards the raw water intake and a project related to the water treatment plant. The total project cost is approximately $7.3 million.
Touching on area population and the demand for water from residents, the report stated the following, shedding light on who else benefits from Outlook's water supply:
"The raw water supply for the Town must be able to provide a sufficient supply of water to all residents and businesses in the Town, the Riverview Golf Course at the south end of Town, and users of the Outlook West Regional Pipeline Association (OWRPA) including the Village of Milden, Milden Hutterite Colony, Dinsmore Hutterite Colony, and approximately 30 farms that are also serviced by the OWRPA. The Town also provides treated water to a regional pipeline to the east of Town, these demands are captured within the Town of Outlook demands identified below.
Since the population of any community changes with time, it is important to ensure that a water system is capable of providing enough capacity to support a growing population. To predict the community’s need for the future, historical population and water consumption data were collected and used to forecast future water usage."
In addition to the regional pipeline located east of Outlook, the Town also supplies treated water to Rudy Landing housing development located north of Town.
Shedding further light on projected water demand, the report theorizes where such demands are possibly headed in Outlook over the next two decades using a number of parameters to predict growth and ensuing demands, including the following:
A baseline 2021 population of 2,516 people (as projected from 2,279 people from the 2016 Stats Canada Census);
An annual growth rate of 2%;
A per-capita demand of 543 L/cap-day (based on raw water demand) and;
A maximum day factor of 2.5.
The projected water demand as it relates to the Town of Outlook includes the following information, using factors that include today and into the future:
Year - 2021
Population - 2,516
Average Day Water Demand (m3/day) - 1,687 (20 L/s)
Annual Water Demand (ML) - 616
Maximum Day Factor - 2.5
Maximum Day Raw Water (m3/day) - 4,180 (48 L/s)
Year - 2041
Population - 3,739
Average Day Water Demand (m3/day) - 2,507 (29 L/s)
Annual Water Demand (ML) - 915
Maximum Day Factor - 2.5
Maximum Day Raw Water (m3/day) - 6,212 (72 L/s)
As well, the report explores several different options for servicing raw water to the Town. What follows is a section that describes potential concept for drawing from the Broderick reservoir:
Sourcing Water from Broderick Reservoir
Drawing raw water directly from Broderick Reservoir would involve an intake conduit with an end-of pipe fish screen within Broderick Reservoir that would convey water from the reservoir to a raw water pump station near Broderick Reservoir. The raw water pump station would pump raw water through a roughly 12-kilometre RWM to the Town’s WTP on Railway Ave. This option would also require an intermediate raw water storage reservoir to provide back-up raw water during Magnicide H dosing events.
The main advantage of drawing water directly from Broderick Reservoir compared to drawing from the B2 canal is that it already has the storage capacity to provide the winter demands when the canals are not in service, and therefore eliminates the requirement for a large intermediate raw water storage reservoir that would be required if drawing directly from the seasonal use B2 canal. The Broderick Reservoir Intake option should still have an intermediate reservoir to store raw water during Magnicide H dosing periods which is anticipated to be significantly smaller than the raw water storage reservoir required for the B2 canal option.
A detailed bathymetric survey of Broderick Reservoir and a hydrotechnical review from NHC is required to confirm whether Broderick Reservoir has adequate depth to accommodate an intake conduit and end of pipefish screens. It should also be noted that dry/drought years like 2021 significantly lower the water level in Broderick Reservoir due to the higher irrigation usage. As such, an intake in Broderick Reservoir may be subject to the same temporary pumping scenarios experienced by the Town’s existing intake when river levels in the SSR are low (like 2019). WSA would also need to ensure adequate volume is left in Broderick Reservoir at the end of each irrigation season to maintain supply to the Town and other users like the Village of Broderick and the pig farm that rely on Broderick Reservoir for raw water.
Key infrastructure components for the Broderick Reservoir Intake alternative include:
- Fish screens and intake conduit in Broderick Reservoir.
- A new raw water pump station at Broderick Reservoir.
- A raw water storage reservoir for raw water supply during Magnicide H dosing events.
- 400 mm diameter RWM from the new raw water pump station to the Town’s WTP.
- Tee connection to the RWM outside of the WTP to accommodate bypass of raw water down to the Town’s existing raw water pump station.
- Upgrades to Electrical, Instrumentation, and Controls (EIC) and flow control valve to control water levels in the wet well of the existing raw water pump station.
- New power and gas servicing to the new pump station; and
- Site access, roadway, and turnaround areas.
As part of the report's Risks and Unknowns section, the SkyTrail walking bridge is mentioned. Closed since late 2013, the bridge is located north of the Town's existing water intake, and it's said that should anything catastrophic happen with the infrastructure, it could create issues with the water supply.
From the report:
Abandoned Rail Bridge: The rail bridge north of the Town’s existing intake was abandoned several years ago and has been closed to public access due to the risk of the bridge collapsing. AE completed the bridge assessment and determined that the slope instability of the eastern river valley has resulted in Pier 1, near the eastern shoreline tilting.
The tilt has caused the buckling of bridge structural steel members that should be in tension. It is anticipated that when it fails, the bridge failure will be catastrophic, in that entire sections of the bridge will collapse. Placing a new intake/fish screen structure within the vicinity of the bridge creates the risk of damage occurring due to falling debris, as well as risking being cut-off from water if a collapse occurs.
It should also be noted that if bridge decommissioning is planned at a future date, the cofferdam required to decommission the bridge would likely cut off the new intake from the river, resulting in the need for temporary pumping for raw water supply during the decommissioning stage.
As far as costs are concerned, Section 6 of the report, 'Opinion of Probable Cost', looks at the numbers including the capital costs for the construction of each of the studied alternatives. Such prices include a 30% contingency for unknown factors and a 15% engineering contingency to account for the next stages of engineering design, geotechnical investigations, and other approvals. It's said that a 'Class D' Opinion of Probable Cost should be considered accurate to within a range of -20% to +30%.
Costs to the Town of Outlook, for example, are broken down as follows:
Broderick Reservoir Intake - $21-$34 million
B2 Canal - $26-$58 million
Groundwater Wells (not viable) - $29-$47 million
Induced Surface Water Wells - $5-$8 million
Direct River Intake - $8-$13 million
The Town of Outlook's Chief Administrative Officer, Kevin Trew says that from his perspective, the draft report's examination of costs related to these five options may in fact boil down to two "realistic" ones, the Induced Surface Water Wells and Direct River Intake directives.
"There is lots of information to that regard in the report," said Kevin. "That was our focus, to differentiate between these two options as the other options are either not viable (Groundwater Wells) or Cost and Space (we would have to run pipes under ground, easements on land, create our own raw water reservoir and purchase land) Prohibitive."
