Years Ending In 9 Bring River Capers

Years ending in the number 9 seem to do something to the Des Lacs River.

Not too many report cards are available of the Mouse in the early years ut over the last 30 years it has acted up in 1939, 1949 and 1969. It behaved in 1959.

What data is available on the Des Lacs was dug out for The News by Milo Hoisveen, state engineer and secretary of the State Water Commission.

It show’s there's no question about the capacity of the Des Lacs for putting on a dilly of a tantrum when the conditions are right. It has a basin of 409.8 square miles to drain, a basin where the temperatures are likely to be quite constant and when a big, sudden thaw comes, it’s like pulling the cork from a bottle.

As was true this year, its water came with a great surge and the 30,000 acre feet that reached Minot left devastation estimated at more than $3 million.

That runoff figure for Minot was only about one eighth of the 230,000 acre feet being dumped in Minot by the mainstream but the Des Lacs impact was great because its water came up so quickly while the flow of the Mouse sustained at a high level over a much longer period. All observers agree if the peak flow from the Des Lacs had come at the same time as the Mouse peak the damage to the city would have been much more grave, perhaps raising the level another two feet in Minot and greatly widening the flood belt.

The Des Lacs began rising rapidly on April 6 and hit its peak flow at Minot on April 11. The Mouse flood waters, on the other hand, will be around for another month.

Two gauges measure the Des Lacs flow. One, at Foxholm, has been installed since 1945. With a reading this year topping 19 feet and a flow of 2,400 cfs, a record at that gauge was set. Hoisveen called that runoff one of a 40 year frequency. In 1949 the flow was 2,000 cfs, a 23 year frequency pattern.

The gauge at Foxholm measures the runoff of the upper 269 square miles of the basin, beginning with the lower dam on the Des Lacs refuge at Kenmare.

Another gauge, near Burlington, is located at the dam which once served as a small irrigation project. It was that gauge which put something on record regarding the high runoff in 1939. At the peak that year the Burlington measurement indicated a flow of 2,000cfs over the dam plus another 730 cfs going through the gates.

That year the snowfall melt wasn’t heavy but the melt was extremely rapid.

However, the 1939 runoff at Burlington was not matched at Minot where the peak flow was 1,480 cfs, well below flood stage. Hoisveen explained the drop by the fact the channel between Burlington and Minot soaked up part of it and an additional amount backed up into the channel of the Mouse River below Lake Darling dam.

Those same two things happened this year when the flow at Burlington peaked at 3,900 cfs while the Minot peak was 2,950cfs.