Hundreds of dead and dying trees due to sustained high water
By Ted Pennekamp
Anglers, boaters and many other people who enjoy the Mississippi River have noticed a large die-off of trees and a lot of erosion on the islands of the river, especially evident this year.
Hundreds of trees have died in Pool 10 and perhaps thousands in the whole Upper Mississippi River.
Acting Regional Hunting and Fishing Chief of the Upper Mississippi River National Wildlife and Fish Refuge–McGregor District, Brandon Jones, said the dead and dying trees will be even more noticeable in 2020. Jones said the sustained high water of the past four years is to blame for this loss of habitat. He said there are numerous areas in the Upper Mississippi River that have had tree die-offs.
“The last four years of high water during the growing season is the reasoning for tree loss observed along the Mississippi River. Areas of great loss in Pool 10 are observed at Gremore Lake and north up Ambrough Slough, McGregor Lake, and the Wisconsin River Delta down toward Wyalusing,” said Jones.
Pools 9 and 11 have also sustained quite a loss as have many other pools in the Upper Mississippi River.
“Pool 9 areas of great loss can be seen from Hayshore Lake north up into Reno Bottoms. Pool 11 areas of great loss can be seen from Bertom to Cassville,” said Jones. “While spring flooding is normal and can be beneficial in some instances, it is the extended duration of flooding (compounded with consecutive years) that causes harm and loss to trees and island erosion.”
Jones said 2019 has been the worst of the past four years for extended high water. The Mississippi was above flood stage for 87 consecutive days this spring and summer. It dropped below flood stage of 16 feet on June 11. The river was also above 13 feet for most the summer. The river at McGregor dropped to approximately 8 feet for only about three weeks before recently bouncing back up again to above 14 feet. It was at 12.97 feet at 7:45 a.m. on Oct. 1 and is predicted to reach 15.7 feet by Oct. 7.
The Mississippi River crested twice at the McGregor gauge in April, at 21.34 feet on April 5 (the sixth highest ever recorded) and 21.75 feet on April 26 (the fourth highest).
“The extended flooding creates poorly drained saturated soils, which prevents the tree roots from receiving oxygen. This, compounded with sediment deposition of three inches or more on trees, can further impede the flow of oxygen,” said Jones. “As the trees die, they become very susceptible to ‘tipping’ either by high wind or high water. Once the trees tip, flood waters carve away at the soil which, in turn, leads to severe erosion of islands and banks. In some instances, eroding away islands completely. The one bright side in all the flooding is that the silver maple trees did produce a good seeding and many little maples were observed. Time will tell if these trees will survive.”