Lake Level Alert — November 2012

November 7th, 2012 Posted by Water Quantity 0 comments on “Lake Level Alert — November 2012”

This communication is to let our members know the projections so you can make decisions about your dock or other issues that will be impacted by a reduction in Lake Lanier levels.

There was a Drought Assessment webinar conducted yesterday. Below is a link for the current forecast for Lake Lanier lake levels.Conditions indicate that Lake Lanier will be under considerable pressure over the next couple of months due to decreased inflow and to increased discharges to meet downstream water flow requirements. 

A few summary points from the webinar are as follows:

  • – Rains during the previous week have been less than 0.5 inches and drought continues throughout the basin except the Florida panhandle
  • – 30-day rainfall totals are less than 20% of normal and rainfall to date this year is 50-80% of normal
  • – The two-year rainfall total is 10 to 30 inches below normal in the basin, with the 2-year rainfall total for Sep 2012 being the lowest since 1900
  • – Inflows to Lake Lanier have dropped sharply and streamflows and ground water remain near historic lows in southern GA and AL
  • – Full basin inflows have dropped below 2000 cfs, well below the 5000 cfs needed to meet minimum flows for the Apalachicola

Compounding our situation is the fact that West Point and Walter F. George lakes are near their conservation zone so they are not able to contribute to the requirement to meet the 5,000 cfs minimum flow into the Apalachicola River. That is why we are seeing discharges of 3,000 – 4,000 cfs from Lanier.

 Also below is the 7 day basin inflow moving average. While this does not accurately represent the actual rainfall into the ACF Basin, it is what the Corps uses to manage the reservoirs and control releases from them. The difference between the 7-day moving average and the 5,000 cfs has to be augmented by the reservoirs. At this point, Lake Lanier is the only reservoir with water available. Based on these projections and the Corps of Engineers operating rules, the flow into Apalachicola River will remain at or near 5,000 cfs until the composite storage in the ACF Basin is back in Zone 1 which will probably be well after the first of the year. The composite is now in Zone 3 and could be in Zone 4 by the end of the year.

 The Corps of Engineers and the climatologist emphasize that since 2000 we have experienced three of the worst droughts ever in the ACF Basin.

 Lanier11052012

7-day moving average 11042012