US Army Corps of Engineers BUILDING STRONG ® USACE – ACF Operations Bailey Crane Water Management USACE, Mobile District

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Mobile District Basins

BUILDING STRONG ®  Conduct water management activities for Corps reservoirs  Supervise flood control  Technical assistance  Exchange data with National Weather Service and provide information to District elements  Operation of rainfall and river reporting network  Maintain project data  Preparation/revision of water control manuals  Develop hydrologic models Water Management – USACE Perspective

BUILDING STRONG ® Water Management Staff  Supervisory Hydraulic Engineer  4 Hydraulic Engineers  1 Engineer Interns  1 Hydrologic Technician Office staffed 365 days/year (limited hours on weekends)

BUILDING STRONG ® 6 Lake Lanier West Point Lake Walter F. George Lake Andrews L&D Lake Seminole/ Woodruff Dam Flint River Chattahoochee River Apalachicola River The ACF Basin Buford Dam and Lake Sidney Lanier

BUILDING STRONG ® Recreation Water Quality Hydropower Navigation Project Purposes and Demands Municipal & Industrial Environmental

BUILDING STRONG ® ACF Major Water Users

BUILDING STRONG ® Minimum Flows on the ACF 5000 cfs Apalachicola R. at Chattahoochee 750 cfs at Peachtree Ck 670 cfs below West Point Lanier and West Point have instantaneous flow requirements; Jim Woodruff has a daily average flow requirement Peachtree Creek Minimum flow below Jim Woodruff varies with RIOP rules

BUILDING STRONG ® ACF Basin Basin Storage When Full: 62.5% - Lake Lanier 17.6% - West Point 14% - W. F. George ACF Storage

BUILDING STRONG ® ACF Drainage Area Lanier 1040 Miles 2 West Point 2210 Miles 2 WF George 4080 Miles 2 Jim Woodruff 9770 Miles 2 Only 6% of Drainage Area!

BUILDING STRONG ® What Does This Mean? West Point and WF George Will fill 3 ½ time faster than Lanier If the reservoirs did not release a drop of Water

BUILDING STRONG ® Current System Drivers  “Balanced System” Operations  State water quality flow requirement near Peachtree Creek on Chattahoochee River  Revised Interim Operating Plan (RIOP)

BUILDING STRONG ® State Water Quality Requirement 1,100- 1,500 cfs minimum release to meet Metro- Atlanta 750/650-cfs WQ flow

BUILDING STRONG ® Revised Interim Operating Plan  Dictates operations based on basin inflow and releases from Jim Woodruff Dam  Year-round operations to support flow needs for sturgeon spawning, young sturgeon, mussels, and host fish for mussels  Minimize or avoid impacts of low flow operations on listed species or critical habitat  Provide for storage when water is more plentiful to allow for future augmentation during low flows in support of mussels  Minimize impact to other project purposes

BUILDING STRONG ® RIOP Operations-Release Decision Matrix

BUILDING STRONG ® How Did We Get Here?

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Historic Low Flows on the Flint  Most flows below the 10 th percentile during late August and September  Daily record lows at numerous gages on many days

BUILDING STRONG ® Woodruff Discharge vs Basin Inflow Woodruff Discharge 7 Day Basin Inflow 5,000 CFS Minimum Release Flow supplemented with storage

BUILDING STRONG ® Forecasting Lake Levels QPF’s CPC Precip Outlooks SERFC River Forecasts

BUILDING STRONG ® Forecasting Lake Levels  Short term forecasts use QPF’s and river flow forecasts  NWS, SERFC  Long term forecast based on predicted climate conditions and forecasted percent of normal rainfall  Climate Prediction Center  Flood forecasts use QPF’s, river flow forecasts, and data collected by project personnel.

BUILDING STRONG ® Lake Lanier ► Authorized by PL ► Completed 1957 ► Authorized Project Purposes Flood ControlHydropower Water QualityWater Supply RecreationNavigation Fish & Wildlife

BUILDING STRONG ® Lake Lanier-5 Week Forecast

BUILDING STRONG ® ► Authorized by PL ► Completed 1975 ► Authorized Project Purposes Flood ControlHydro Power RecreationWater Quality NavigationFish/Wildlife West Point

BUILDING STRONG ® West Point-5 Week Forecast

BUILDING STRONG ® ► Authorized by PL ► Completed 1963 ► Authorized Project Purposes Hydro Power Water Quality RecreationFish/Wildlife Navigation Walter F. George

BUILDING STRONG ® Walter F. George-5 Week Forecast

BUILDING STRONG ® Remaining Composite Storage in the ACF 5 Week Forecast

BUILDING STRONG ® Long-Term Outlook

BUILDING STRONG ® 3 Month Precipitation Outlook

BUILDING STRONG ® Long-Term Forecasts  Developed using ACF ResSim Baseline Model  Based on percentile flows of entire period of record

BUILDING STRONG ® Lake Lanier – 3 Month Forecast 2011 Observed Elevations 10 th Percentile Hydrology 25 th Percentile Hydrology 50 th Percentile Hydrology Top of Conservation

BUILDING STRONG ® West Point -3 Month Forecast 2011 Observed Elevations 10 th Percentile Hydrology 25 th Percentile Hydrology 50 th Percentile Hydrology Top of Conservation

BUILDING STRONG ® Walter F. George - 3 Month Forecast 2011 Observed Elevations 10 th Percentile Hydrology 25 th Percentile Hydrology 50 th Percentile Hydrology Top of Conservation

BUILDING STRONG ® Summary  Conditions for the upcoming fall and spring are forecast to be drier than normal as La Nina conditions persist  Full refill of storage projects on the ACF is unlikely for the upcoming year  The Corps will take advantage of opportunities to store water while meeting basin-wide needs and project purposes