For the past few weeks I've been waiting to do another flood diary. But there ain't been much news- we've had a slow melt here in southern Minnesota, same in northern Iowa. Thus the flood predictions for the Minnesota River watershed have been ratcheted down a few notches- we're getting flooding but little of the record or even major variety. It's a hassle, with some local roads and railroads closed and closing of gaps in the levees, but we're not seeing any cities flooding or rivers expanding to flood entire sections of farmland. But the snowmass in northern Minnesota and North Dakota ain't budged a bit, thanks to unseasonably below freezing temps. To give you an idea of the remaining flood potential here's a link to a Nation Weather Service (NWS) map of snow water content in the midwest. Note that there's over 4 inches of water content remaining in the snowmass in much of northern Minnesota and North Dakota and 6 inches and more in places. Here's a link to the NWS long term probalistic flood forecast for the area. Note that most of the red dots indicating an 80% or more chance of severe flooding are in the Red River valley.
And for the Red River valley, no news is not good news when spring has sprung and you've still got a major snowmass on the ground. This is a broad and flat river valley, in fact one of the flattest areas in the world. The Red River drops less than a foot a mile, which isn't exactly conductive to rapid movement of flood waters out of the watershed. The last few years the valley has seen record and near record floods, but thanks to an early spring melt the rivers have crested and started dropping by this time of the year. Back to the NWS charts- here's a probalistic forecast for river levels in Fargo, note where the columns turn from blue to red- that's the 50% probability line. The NWS is predicting a 50% chance of major flooding from the 2nd week of April through the middle of May. That will mostly end the flood battle in the cities, but most of the farmland in the valley isn't protected by levees and will be under water until the river drops below flood stage. The river is already above flood stage along much of it's course, and the NWS is predicting a 50% chance that it won't drop below flood stage until the middle of June. Add a week or three to that for the fields to dry out enough to allow planting...
The Red River valley is know for some of the most fertile ground on the planet and a short growing season. Field work in the valley usually commences around the middle of April, with the last frost in the third week or so of May. The first frost of fall usually ends the growing season around the third week of september. Thus farmers in the valley get justifiably nervous if they haven't been able to plant by Memorial Day... Wheat needs a 110 to 130 day growing season, and corn and soy beans need even longer between frosts.
After the 1997 flood over 800,000 acres in the Red River valley finally dried out too late for planting. This year's flood looks to inundate just as much acreage, and prices for wheat and other crops have doubled and tripled since 1997. It's not unusual for an acre to produce a thousand dollars worth of crops a year, and we're looking at the better part of a million acres that may be underwater through much of June and unplanted this season. Yup, we're looking at around a billion dollars in potential economic losses from this late flood. A couple hundred thousand folks live in the valley, and around 20% of them rely on agriculture and food processing for their livelyhood. So we're looking at billions of dollars in economic losses due to this flood in the Red River Valley alone, even if no cities are flooded. On a worldwide scale, with wheat inventories low, we're looking at an economic tusumi if the Red River valley, one of the worlds major granaries, is taken out of production by this year's prolonged flooding...