Flooding remains a definite concern in the city in spite of millions being invested.
More work needs to be done René Richard, Director of Engineering and Asset Management with the City told the regular meeting of Yorkton Council Monday.
But before more work is undertaken a more complete, city-wide plan is required, said Richard.
“In recent years, we have been experiencing significant rainfall increases,” he told Council. “We have also been experiencing more intense rain events that have exceeded the capacity of our storm system in certain areas resulting in localized flooding.”
Typically the storm sewer minor system (underground pipes) is designed to handle a storm event of about one inch per hour, detailed a report circulated to Council Monday. In older areas, the standard was about three-quarters of an inch in one hour.
Events that have greater amounts or more intense events will result in temporary water ponding on streets. The depth and duration of the ponding will vary depending on the location. The system is designed to include some ponding, but in some cases, the ponding is so deep that houses are being flooded.
“Since 2010, the City of Yorkton has spent over $9,500,000 on overland drainage,” said Richard. “This includes mostly the Brodie Pond and the channel and ponds on Dracup Avenue.
“Also, piping was upgraded along Dracup Avenue at a cost $6,400,000.
“This was important work that needed to be done, but it is clear that with intense rainfall happening more and more frequently, there is more work to be done.”
Some work is already planned.
“We are currently in the design phase for ditch work and the replacement of the culverts under HWY 9 just north of York Road at an estimated cost of $4,800,000,” said Richard. “These culverts handle all the storm water from the Dracup and Victoria ditches which accounts for approximately 90 per cent of our total storm water. This project will significantly improve the performance of our system.
The city is also planning to clear out the vegetation along the Victoria ditch in 2016.
“Between what has been done since 2010 and what improvements are currently budgeted for, there will be around $20,000,000 of investment made to our storm sewer system by the end of 2018,” said Richard.
Richard said in response to concerns from citizens, the Public Works Department has noted there are 11 areas of concern throughout the City that still experience significant problems during intense rain events.
“As part of design phase for the Highway 9 culverts, our consultants have developed a City wide storm sewer model supported by a topographical survey by airplane called LiDAR.” he said. “Having this model will allow the consultant to try different potential remedies for any problem area and see how the system would perform locally and overall.
“We do not want to alleviate a problem in one area only to cause one in another area. Not until the modeling has been complete can we determine the type of remedy and potential cost to alleviate the problem areas.”
Richard said with known areas of concern they know where they want to improve run-off water management.
“We would like to begin a project to address those 11 problem areas,” he said.
Those areas would be modelled to identify possible options to alleviate flooding as well as cost estimates to perform the construction of various options, he said.
Richard said, the project will cost approximately $100,000 and could be completed by Dec. 31.
The funds for the preparation project will be made available through the 2017 capital budget, but the work will begin immediately.
