Attorney General Chris Koster today sent a letter to President Obama asking him to declare an emergency to avert a shut-down of commercial navigation on the Mississippi River.

Koster says the drought conditions in the Mississippi River basin, along with Army Corps of Engineers’ plan to reduce flows from the dams on the upper Missouri, threatens commercial transportation because of the presence of rock pinnacles near Grand Tower and Thebes, Illinois.

Koster said the emergency declaration is necessary to fast-track efforts by the Corps to remove the hazardous rock pinnacles.

Koster is also asking the President to direct the Corps to take all necessary action to maintain flow support from the Missouri River system for downstream navigation until the pinnacles can be removed.