The US Army Corps of Engineers has released another piece of the puzzle used to put together future plans for managing the flow of the Missouri River. Army Corps of Engineers officials have released a biological assessment designed to guide the writing of the new master manual for management of the Missouri River. One of the provisions in the assessment would hold more water in upstream reservoirs. The Corps’ project manager for updating the manual, Rosemary Hargrave, says that could cut the barge navigation season significantly if this year’s drought is repeated next summer, perhaps by as much as a month.State Attorney General Jay Nixon focuses on what has been left out of the assessment: an artificial spring flood and low summer flows. Nixon also believes he’ll be able to get any possible lost navigation time back if there is enough water being held in the upstream dams if and when the shortening of the barge season comes up.