Thursday, June 24, 2010 — THE MEDICINE HAT NEWS


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Swift Current avoids threat of evacuation


Swift Current avoids threat of evacuation


News Photo Allison Werbowetsky


As of Tuesday, June 22, bike paths and walkways remained blocked off at the Southside Park in Swift Current and remain completely submerged in water. Later that evening, a Swift Current youth almost drowned in the Swift Current Creek near the park, when he was pulled by the under toe ignoring the signs to avoid the area. He sustained minor injuries and is reported to be fi ne.


ALLISON WERBOWETSKY Prairie Post


Now that the rainstorms and downpours have at least temporarily subsided, residents of Swift Current can once again breathe a sigh of relief. The water levels at Duncairn Reservoir, which feeds into the Swift Current Creek, have slowly begun to drop back down to normal.


Water is currently being released from the reservoir and into the creek at a rate of 1,500 cubic feet per second (cfs). Typically, no more than 15 cfs are released from the reservoir, which is why the water levels in the creek remain quite high.


Water will continue to be released at 1,500 cfs until this Friday. If the rain subsides and the sunshine continues to linger, Swift Current can expect the creek to begin receding and back to much safer water levels by next week.


“We expect the creek to go down to slightly higher than average levels and return to normal, but that all depends on the weather,” said Matt Noble, chief administrative offi cer for the City of Swift Current.


The creek is fed not only by water released from the reservoir, but by runoff fl owing in from the drainage basin and 40-kilometre stretch between Duncairn and the city. The runoff has been contributing an estimated additional 500 cfs.


“The ground is totally saturated, so it’s not going to soak any of that up. It just rolls off, and it takes a little bit of time to go through the gullies and waterways until it reaches the creek,” he said.


The water fl ow from the reservoir is managed by the Saskatchewan Watershed Authority, and typically kept out of the hands of the City. Gord Hagen, supervisor of regional operations at the Watershed Authority in Swift Current, measures the runoff with a hydrometric station located above the reservoir, about halfway up the basin.


“The fl ows that are indicated at that point give us an indication as to what’s coming into the reservoir on the


mainstream. There are other tributaries that come in as well, and, of course, the other tributaries aren’t metred so you have to watch to see what the rise in water levels are in the reservoir as well as looking at the hydrometric station to get a sense of how much (total) water is coming in,” Hagen said.


Prior to the big rainstorm of June 17 - 18, the reservoir was at full capacity — which may seem dangerous, but as Hagen says, it’s actually fairly typical. The reservoir is equipped with extra space that allows an additional foot of water to be held there.


“We have some surcharge capacity to handle rainstorm activities coming in ... and that gives us enough time to react and start making releases,” he said.


As soon as the water levels peaked at one foot over capacity, the dam was opened and water from the reservoir began fl owing into the creek during the morning hours of June 18 at a rate of 750 cfs. However, as the rain refused to let up and the realization that water wasn’t being released fast enough set in, that rate was increased to 2,000 cfs in only a matter of hours.


It took about 18 hours for all that water to fl ow through the city, forcing the creek’s water levels to rise drastically.


“The concern was raised for me when they said they needed to raise it from 750 cfs to possibly 2,000 cfs. Then we started to question them heavily about the potential for things to happen here The main fear was if they were overfl owing at the dam and continued to receive infl ows beyond the outfl ow ... They were releasing 2,000 cfs — if they needed to increase that to 2,500 cfs or 3,000 cfs, then we would have had a fl ood here for sure,” Noble said.


The creek hit its highest point at 53 centimetres over normal at a spot near the water treatment plant just east of the city.


“From the City’s perspective, this all happened in a matter of hours. We had no time to react, so the worst thing we could do is overreact. We managed the


information, we did onsite inspections, we had our engineering guys measuring the creek scientifi cally and doing the calculations to give us the probable outcomes of various scenarios so we could make a decision. We were really in a no man’s land here because we’ve never really had this before in the summertime. It was scary,” Noble continued.


At one point of time, and at worst case scenario, the possibility of an evacuation was considered as the only option.


“It was in our plan but we never got to that stage. Given the size of the creek going through here ... sand bagging would have been a wasted effort. There was no time and there was no labour. When you’re getting that much free-fl ow water on such short notice, the only thing you can do is protect lives. You can’t protect property, it’s impossible, there’s not enough labour in this city, not enough material and not enough sand bags. With the timing being what is was ... the only thing we can do is manage evacuation routes,” he said.


Although the persistent rainstorms of last week were predicted early in advance, Hagen and the Watershed Authority didn’t want to begin releasing water from the reservoir too soon. After all, Duncairn is a storage reservoir used for both municipal and irrigation needs. Its water is preserved for periods of lengthy drought.


“We’re always interested in having it as full as possible. We’ve come through about 10 years of drought conditions where we’ve had to carry over water from one year to the next to meet our needs ... so you always have to look ahead to that point ... We could not have anticipated some of the runoff events we’ve had here certainly in the last little while,” Hagen said.


Luckily, at no point was there any fear that the dam would break.


“None at all. Duncairn is a very safe dam,” he said.


Havoc on the highways Havoc on the highways


CHRIS JASTER Prairie Post


The water from the creeks around Maple Creek didn't just wreak havoc in the RM and Town of Maple Creek, it also caused a lot of problems with the highways.


A culvert under the westbound lane of the Trans-Canada Highway near the Eagle Valley Campground failed on Friday and the water caused a 75-metre section of the highway to collapse, forcing the Ministry of Highways to close the Trans- Canada Highway on June 18.


"What will happen when you have extremely high infl ows of water and a high velocity of water fl ow is as water backs up it will start to erode the dirt around the culvert and then as the water keeps fl owing in it starts to bore into the substructure of the road until you get a void and then the highway just collapses," said Doug Wakabayashi, the director of communications for the Ministry of Highways and Infrastructure.


Part of the eastbound passing lane was also damaged by the water. The Ministry of Highways brought in crews from Regina, Moose Jaw and Weyburn to try to repair the eastbound portion of the road so it can re-open the highway.


Highway repair crews hauled in approximately 7,000 tonnes of aggregate material on June 21 and crews established access to the hole to try to rebuild the eastbound lane — which will carry two-way traffi c from when the highway re-opens until the westbound lane is reconstructed. The westbound lane has to go back to the design stage and, as a result, Wakabayashi couldn't estimate how much it will cost to repair the roads.


Wakabayashi initially hoped reconstructing the eastbound lane, which will have permanent repairs done to it after the westbound lane is reconstructed and open, would be fi nished


by Wednesday, but it appears it won't be fi nished until later today or this weekend.


"I think part of (the reason for the delay) is the extent of the damage," said Wakabayashi in a conference call on Tuesday. "It's requiring us to bring in more material and as we bring in more material, we start to deplete our aggregate resources close to the failure and it's resulting in some longer hauls, but the work itself is resulting nicely."


That section, however, wasn't the only part of the Trans- Canada Highway that was fl ooded with water on June 18. Approximately three kilometres of the major throughway near the Alberta boundary had water covering it for four days.


The damage to that section of the Trans-Canada Highway was limited to the shoulders and sideslopes, which are still being repaired.


These repairs, however, are minor compared to what happened near the Eagle Valley Campground and won't affect the timeline for the highway to re-open. That depends entirely on the reconstruction of the eastbound lane near Eagle Valley.


If the Trans-Canada Highway is not open by the weekend, the Ministry is asking people travelling to Alberta to take Highway 4 north at Swift Current and then travel on Highway 7 to Alberta, the same path people have been using since the highway closed on June 18.


The Trans-Canada Highway wasn't the only Saskatchewan highway hit by the fl ood. The rushing water completely destroyed a bridge about 27 kilometres southwest of Maple Creek on Highway 271.


The bridge failure forced the highway, which connects Maple Creek to Fort Walsh, to close on June 18, and it will be closed until the middle of July.


After initially planning to install a temporary bridge during the Canada Day weekend and rebuilding the bridge at a later date, the Ministry of Highways and Infrastructure found in- stock material and will rebuild the bridge. Construction is set to begin this weekend and the Ministry hopes the highway will re-open on July 1.


Drivers who need to drive to on this section of Highway 271 may take Highway 21 to Highway 13 and then connect back north on Grid Road 615, which is about a 150-kilometre detour, or they may use trails that locals know about. The Ministry is OK with drivers using the trails even though they weren't built for much traffi c because it's a low-use highway.


Highway 21 was also shut down on June 18 because of the water fl owing into Maple Creek. That forced Cypress Hills Interprovincial Park to close for the fi rst time in its history.


There was only minor damage on that roadway, as Highway 21, which brings traffi c north into Maple Creek, was re- opened on June 19. It was shut down for three hours later on so crews could repair a bridge abutment. That road, however, was back open at 11 p.m. that night.


The Ministry brought in equipment and approximately 30 extra people from Weyburn, Moose Jaw, Kindersley and Regina to work on the highways.


"Our crews have done all they can do to keep provincial highways open and operating, not withstanding the failure on Highway 1 of course," said Wakabayashi. "We are doing everything we can to restore service on Highway 1 as soon as we can and also throughout the weekend we continue to work with the towns and RMs to provide them with what assistance we can."


The Ministry is asking for people to check the Highway Hotline before travelling.


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