Recent snowfall good news for irrigators

By Al Beeber - Lethbridge Herald on March 26, 2024.

LETHBRIDGE HERALDabeeber@lethbridgeherald.com

Snowfall in the past week is good news for the southern Alberta drought situation.
David Westwood, general manager of the St. Mary River Irrigation District, said Monday there is some optimism moving forward.
“It’ll have a positive impact. It’s not going to solve all our problems by any means. Our storage is still quite low compared to normal years,” said Westwood.
Early numbers show an uptick “and obviously it’ll translate into some more reservoir storage so it’ll be helpful, there’s no question but it won’t solve all of our problems,” with more snow and precipitation needed this spring, he said.
The drought conditions as 2023 ended looked dire, he said, and into January there still hadn’t been much snow.
“But this last little bit in March is definitely raising, at least for us, in the southern tributaries and the South Saskatchewan and the Oldman River basin, it’s starting to show an uptick so where we saw it was going to be maybe a little bit more conservative, we’re thinking that while we’re still going to have restrictions – there’s no question about it – I think to start irrigation season around the province, the restrictions might not be as severe as we were once thinking they could be if we continued through a winter with basically not getting any help.
“But this snow we’re receiving this spring is definitely quite welcome,” he added, with the recent accumulation being a pretty good one.
Information SMRID has been recently receiving has been comparing the current situation to the drought in 2001 which this year is shaping up to be similar to, he said.
“2001 was for sure one of our lower water levels in the whole southern Alberta and we had pretty severe restrictions that year and that continued throughout the whole season and into 2002 we started with low allocation in our district,” he noted.
The spring of 2002 saw a significant amount of precipitation arrive in May which filled the reservoirs considerably, turning a dry situation into a good year, he said.
The province has 11 irrigation districts with different watersheds. The province monitors all the river flow to ensure there is enough in-stream flow to meet apportionment.
Irrigation districts have to let 50 per cent of water pass to Saskatchewan “so we always have to be cognizant of that.” Each district will have a source of its sub-basin.
“We all look at our sources very uniquely and then determine what we think we’re going to have for our water availability,” said Westwood.
“There’s a lot of moving parts.”
SMRID’s board, it said in a March 15 update to irrigators, is forecasting a preliminary water allocation of eight inches at the farm gate to start the 2024 season.
This forecast could be subject to change and will be finalized at SMRID’s annual general meeting April 3 at the Agri-Food Hub and Trade Centre in Lethbridge.
Last week’s update, before the storm hit southern Alberta, stated that both the Akamina and Many Glacier snow pillows have increased significantly from the last week of February to March 11 but still remained below the levels of 2001.
THE SMRID expects that the six irrigation districts along the southern tributaries will be participating in water-sharing memorandums of understanding but all the voluntary participants have yet to be finalized.
As of last week, there is 292,000 acre feet of storage for the entire St. Mary Project, which represents 48 per cent of the SMRID’s combined headworks and district reservoirs winter storage target levels.
The headworks reservoirs include the Waterton, St. Mary and Milk River Ridge reservoirs, which as of March 15 had a storage level of 147,000 acre feet.
The winter storage target is 611,000 acre feet, which is estimated at 78 per cent of the district’s irrigation storage full supply limit to accommodate spring runoff and precipitation.
Since last Wednesday, 40.4 centimetres of the white stuff has fallen on Lethbridge, giving the city much needed moisture.
The data from weatherstats.ca shows that 13.5 cm fell Wednesday with the biggest dump here being on Thursday when we got 15.5 cm of snow. Another three cm fell on Friday before the early spring storm brought 8.4 more cm on Saturday.
That snowfall amounts to 15.9 inches over a five-day period.

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