By J.W. Schnarr
The Southern Regional Stormwater Management Plan has now been completed, though there may still be some issues to work out.
“The regional study is pretty much complete,” said Jack Dunsmore, director of planning and infrastructure. “However, the technical committee wanted to talk a little bit about land costs being included. We do have information back now regarding those costs.”
The area being studied is bounded on the north by the Oldman River and South Saskatchewan River, and extends south and west to include the entire drainage area of the St. Mary’s River Irrigation District main canal, the most significant drainage feature in the region.
The eastern boundary is defined by the drainage basin of Seven Persons Creek, which discharges into the South Saskatchewan River in Medicine Hat.
In all, the study area comprises 8,000 sq. kilometres (2,000,000 acres) of land, the vast majority of which (61 per cent) is non-irrigated and private irrigation farmland. In 2010, a 1:100 year rainfall (one per cent chance each year over 100 years) in the eastern and western portions of the study area caused dramatic flooding events across the southern portion of the province.
In the rest of the area, rainfall was significantly less, amounting to somewhere between a 1:10 and 1:25 year event. While rainfall was much lower in 2011, overland flooding again occurred during dramatic snowmelts and drainage channel restrictions caused by snow and ice.
Again in 2013, flooding occurred in the area but it was primarily limited to Medicine Hat. The flooding was caused by rainfall outside the study area in the Rocky Mountains and foothills leading to high flows in the Bow River basin. In total, the study proposes seven mitigation options throughout the area studied, with a total price tag of $151 million. These options include:
Chin Reservoir expansion, $39 million;
Horsefly Spillway, $46 million;
Sherburne Spillway and Reservoir Expansion, $13 million;
Sauder (Rattlesnake) Reservoir Spillway, $13 million;
Murray Reservoir Expansion, $25 million;
Paradise Creek Dry Dam, $13 million; and
Drain Inlet Pumping Stations (20 sites), $2 million.
In updating council, Dunsmore said while he was satisfied with the majority of the plan, there seemed to be some areas which needed more work.
“There’s a few things I’ve been reading through there, and they have to make a little bit better explanation in my mind about some of the hotspot areas,” he said. He noted Yellow Lake in particular has been addressed, but his opinion was that it needed more work.
“They’ve addressed it, but it has to be addressed some more.”
Following discussion, council motioned to send a letter of support regarding a request for the provincial government to allocate funds toward the different projects identified within the plan.