Madeline Luke, Published January 09 2011
Apply science to Devils LakeI am glad to see that The Forum sees a connection between Devils Lake and the Red River Valley (Dec. 11 editorial). A few numbers, however, are useful to get a fuller picture.
At 1,451.3 feet above mean sea level, the lake is about 75 percent full. An additional 1.4 million acre-feet is needed before it reaches an elevation of 1,458 feet, then water flows through the Tolna Coulee into the Sheyenne River, on the way to the Red River.
The Army Corps of Engineers in 2003 stated that armoring the coulee with a concrete drop structure ($1.1 million) to prevent erosion of the coulee would protect downstream communities. Its 1999 model stated that a flow of 12,000 cubic feet per second would result in the worst possible flood
(1.1 million acre-feet, about twice the 2009 upper basin inflow) – an occurrence with an already full lake (1-in-70,000 probability) and erosion. This worst-case scenario flow would be decreased to 1,740 cubic feet per second with armoring. The overflow would be only 530 cubic feet per second for a full lake, a 100-year flood like 2009 and armoring. What is the emergency for downstream communities if the coulee is armored at 1,458 feet?
On a July 4 flyover of the Devils Lake upper basin,township after township of farmed, drained wetlands were seen. An estimated 200,000 acres of restored wetlands could hold up to 600,000 acre-feet of water every year; this water would not get into Devils Lake.
The Red River in Fargo was at flood stage last fall with the Devils Lake west bay outlet contributing 250 cubic feet per second. Now, outlets pumping 650 to 1,000 cubic feet per second total are proposed to lower the lake level. Water from Devils Lake takes about one week to reach the lower Sheyenne Valley, so turning off the pumps when a sudden heavy summer or fall rain occurs is quite useless in preventing a flood. A 20 percent reduction in upper basin inflow for the entire Red River Basin is part of the plan to address spring flooding. How does an extra 650 cubic feet per second or more from Devils Lake affect this target or the requirements of the Fargo-Moorhead diversion?
A few more numbers to consider:
- $90 million requested by Fargo and West Fargo for a water plant upgrade to handle the sulfate-rich water. Perhaps higher water bills to run this energy-intensive plant.
- $1.6 million designate for repairs to West Fargo Sheyenne River diversion last month. This earthen dike will need continuous repairs because of erosion from the constant high flow.
- About $1 billion to move homes, protect infrastructure at Devils Lake; not much to help the farmers who lost the use of their land.
- No estimates on the value of ruined Sheyenne River ecosystem, damages from flooding and erosion in the Sheyenne Valley, loss of National Fish Hatchery and recreational opportunities on the Sheyenne.
It is time to use science and economics to address the Devils Lake issue effectively, efficiently and equitably.