by Chris Clayton, DTN Ag Policy Editor
OMAHA (DTN) — A panel of outside experts brought in by the Corps of Engineers to study the Corps’ decision-making during this year’s flooding on the Missouri River found no acts of negligence or problems that helped create or exacerbate the flooding.
The Corps released a 99-page report Tuesday written by members of the National Weather Service, USDA’s Natural Resources Conservation Service, U.S. Geological Survey and Colorado State University who work on water data and studies.
In examining the events and forecasting leading up to record volumes of water flowing down and across the Missouri River’s series of dams and levees, the report noted: “The Corps’ long-term regulation forecasts did not accurately account for the runoff volume, however, no forecasting agency accurately predicted the volume of the extreme runoff.”
Brig. Gen. John McMahon, commander of the Northwest region for the Corps, stressed that the panel was independent. The report provided a chance to learn and improve the Corps’ river management.
“This is a very important opportunity as a first step for the Corps’ to be held accountable to the people in the Missouri River basin who we serve,” McMahon said in a conference call Tuesday with reporters.
The report notes the Corps of Engineers followed its Master Manual for the Missouri River in making decisions regarding water storage and releases from dams. One of the first statements in the report is that the operation of the reservoirs must conform to guidance in the Master Manual “and the decisions were appropriate and in line with the appropriate manuals.”
“Looking at the event in hindsight, it’s true that more flood storage and earlier releases could have reduced the impact of the flood,” said Neil Grigg, a civil engineering professor at Colorado State University. “But the master manual would have to be revised to allow for this.”
Grigg said the Corps of Engineers has eight major authorized mandates for managing the Missouri River, including for such purposes as recreation, environmental protection, river navigation and flood control.
“It’s important to understand there is a tricky balance in trying to find the optimum way to operate the system,” Grigg said.
The panel defended the Corps, pointing out that even before the flooding became a downstream crisis there were people complaining about the Corps’ releasing too much water from the reservoirs in early spring.
“The Corps has a really difficult job satisfying everybody along the river,” said Bill Lawrence, a hydrologist with the National Weather Service. “Everybody was saying ‘Why didn’t they release more water?’ Well, it’s a fact that even when they were increasing releases in March and April, they were getting nasty emails from people downstream asking ‘Why are you releasing so much water?’ They have a very difficult job.”
Rainfall in Montana in May set records with amounts from 6 to 10 inches over a swath of land as large as 60,000 square miles.
People questioned throughout the flooding whether the Corps had paid too much attention to environmental mandates and endangered species at the expense of communities and property. The report states that was not the case.
“We found no evidence that was a factor,” Grigg said.
At the same time, the panel did not find evidence that operation of the Missouri River was affected by flooding along the Mississippi River that actually began weeks earlier. Corps’ officials made decisions to protect the dam infrastructure, thus reducing possibly more catastrophic floods.
“The serious consequences of dam failure require the operators to take precautions such as to evacuate flood waters and increase releases as they did in 2011,” the report stated.
Still, the panel noted all of the manuals, data collection, forecasting and decision making can be improved. In particular, the Corps could do a much better job communicating the risks of flooding to the public.
At the end of 2010, the Corps had left 16.3 million acre feet of space throughout the six major dams to handle melting snow pack and spring rain runoff. Snow melt filled the system faster than expected. Heavy rains and runoff in May overwhelmed the system, causing the 150,000 cubic-feet-per-second release of water from the Gavin’s Point dam that was increased to 160,000 cfs in mid-June.
Runoff in 2011 reached 60.8 million acre feet of water in 2011, nearly 20{fe867fa2be02a5a45e8bbb747b653fe2e9d0331fd056b85cd0c1a3542435a96e} more water than the prior record level set in 1997.
The panel also examined challenges from increased development in the floodplains throughout the Missouri River system. Too many people not only didn’t think their communities or locations could flood, but many people were upset that they didn’t have enough early notice to buy flood insurance.
“One of the things we noted is people in the basin need to understand better the risk, and in fact, it’s a shared risk,” Grigg said.
Both the Corps and communities need to better educate the public about risk communication and floodplain management, Grigg said.
Heading into 2012, McMahon said the storage capacity right now is comparable to last year, but the Corps continues monitoring changes in precipitation and plans to “take a flexible posture” going into next spring.
Here’s a link to the full report: http://www.nwd.usace.army.mil/…
© Copyright 2011 DTN/The Progressive Farmer, A Telvent Brand. All rights reserved.
Posted with DTN Permission by Haylie Shipp
