A Winter Flood

The numerous December thunderstorms that lashed the American Midwest have produced extensive flooding throughout the Mississippi River watershed.  While the crest of the flood is reported to have passed to the south of St. Louis, the Missouri and its tributaries are still running high and flooding along the Illinois River is not expected to peak for another few days.  According to hydrologists, the crest of the Mississippi flood will not reach New Orleans until January 19.

Crossing the Mississippi just north of St. Louis this morning, we observed widespread flooding, especially along the Illinois side of the river.  Farther east, almost all of the Illinois streams that pass beneath I-70 were bank full and the Wabash River (a major tributary of the Ohio and thus a secondary tributary of the Mississippi) is still spilling across its floodplain.

Midwestern floods are most common in late winter or early spring, when snowmelt and heavy rains run across frozen ground and when dormant trees are not actively transporting moisture from the soil to the atmosphere.  This winter flood, spawned by an El Nino weather pattern and likely aggravated by our warming climate, may prove to be especially disastrous if a normal or heavy spring flood season follows in its wake.  Saturated soil from the current flood will not absorb the early spring rains, runoff will be excessive and the Mississippi levee system will be stressed; as we have observed in the past, our ability to control nature's fury has its limitations.