The City of Yorkton continues to develop a drainage plan for the west side of the city.
The City has engaged Associated Engineering to complete the Yorkton West Storm Drainage Study, explained Gord Shaw Director of Planning & Engineering at the regular meeting of Council Monday.
"The Yorkton West area is one of the older areas of the city. The majority of it was constructed before 1980. In spite of the upgrades that have been made to the drainage system throughout the years, ongoing development has increased runoff volumes and peak flow rates. These rates exceed the capacity of the existing drainage system. Although the existing system performs adequately during times of low flow surcharging and flooding frequently occur during large storm events," detailed a report from Shaw circulated to Council Monday.
"The July 1, 2010, storm event was greater than a 1:100 year event and any storm water system is not designed to convey the flows associated with it. Instead, most communities typically construct facilities for lesser events, i.e., 1:2, 1:5 or 1:25 years. Associated Engineering modeled the results of a 1:25 year event as this is anticipated to occur more frequently than the 1:100 year event."
Shaw said even with the plan completed there will still be flooding in select areas of the study area.
The plan is a multi-faceted one including such aspects as;
Lowering the Victoria Avenue ditch by 1.4 m at the outlet just south of Smith Street;
Upgrade the existing culvert system at York Road;
Add a new storm sewer line to provide connectivity between the Brodie Avenue system and the Victoria Avenue ditch system; and,
Add a surge pond immediately east of Brodie Avenue.
The benefit of making these improvements is significant areas along Laurier Avenue, Brodie Avenue, Broadway Street West and Maple Avenue can be relieved from significant flooding.
The extensive work would not come without a cost. Associated Engineering identified the cost for doing this work as likely in the range of $16,000,000 once engineering, contingency and construction is included, said Shaw.
While the cost of the project is significant Shaw added it would be "spread out over many, many, many years."
The next step is to review the solution and determine what can be done within the existing budget and resources and what needs to be implemented over the long-term as funding is available, explained Shaw.
It is important to note that Associated Engineering identified that the city needs to compile a complete database for the storm sewer inverts in the vicinity of the proposed improvements based on the available record drawing as well as additional survey and that the model be updated to include this data, he added.
Councillor Les Arnelien questioned if investing in more study made sense if there is not money to do the work identified.
"It is necessary," assured Shaw, adding as it stands "we don't have this information to fit into the model," and that is required to fine tune the final project design.
Coun. Bob Maloney said he appreciated the work needs to move forward.
"I think the community feels this is a priority," he said, adding business and homeowners want some assurance they will not be flooded every three years.
Coun. Larry Pearen agreed stating, "We don't have an option."
"We know we have an issue," said Coun. Ross Fisher, adding additional study will detail how best to implement the plan.
The document passed unanimously Monday included seven recommendations from City Administration including;
The Yorkton West Storm Drainage Study prepared by Associated Engineering is accepted as a long-term action plan to address storm water management in the Yorkton West area as funding and resources are available.
The extensive upgrade concept identified as SCO10 in the report be adopted as the long-term solution to storm water management in the Yorkton West area as funding and resources are available.
Administration is directed to work with Associated Engineering to prepare a scope of work and budget for the advanced engineering required for the extensive upgrade concept SCO10 and report back to City Council when those numbers are available.
