This is not actually a weather question, but is related to our rainfall: What governs how much water the army corps of engineers releases from falls lake? Usually, during the summer, they fix the flow at a low level and leave it there, when the lake is below it's normal level of 251.5'. This year, they have been running it much higher, well above the average flow. This flow dwarfs our water consumption, and is the primary reason for the drop in the lake. I assume they have to meet flow requirements down stream, but have not been able to find anything on the subject.
Posted August 1, 2007
MIKE MOSS SAYS: Andy, In some drought situations, the Corps of Engineers will issue a periodic discussion summarizing the ongoing decision-making process for balancing regional lake levels and downstream river flows. The modest dry conditions so far this year have not resulted in a need for those kinds of regular information releases. However, I did get in touch with the CoE Water Control Manager for our district about your question. Here is his reply to the question of factors currently being considered to set release rates for Falls Lake:
"We have two target flows downstream of Falls Dam. In the summer time, we have a 100 cfs minimum release and a minimum target flow of 254 cfs downstream at Clayton. There are some variables we have to consider in what we release including:
How much treated waste water and when is the water released by the City of Raleigh? How much water and when are other releases into the Neuse River between Falls Dam and Clayton. Many times in order to not go below the 254 cfs target flow, a little extra water needs to be released. Bottom line, what is released from Falls Dam is 254 cfs minus local inflows between Falls Dam and Clayton plus a little bit more.
In some previous serious droughts, we have requested and received special permission from our corporate office in Atlanta to reduce releases and target flows. But this is only done IF our major partners in both State and Federal water resource and water quality offices support this effort to extend the possible storage in Falls Lake."