Inflow forecast

modeled

NOAA’s National Water Model, short-range run issued Sep 29, 11 AM EDT, for the 3 gauged tributary reaches feeding Allatoona Lake. The model includes rain that has already fallen plus the near-term rain forecast.

Gauged inflow now

218

cfs · measured

Peak next 18h

273

cfs · ~Wed 5 AM EDT · modeled

Projected volume

360

acre-feet over 18h · modeled

Net lake effect

−0.01 ft

after 330 cfs out · inferred

Projected flow by tributary reach

Forecast inflow, next 17 hours, all gauged reaches: starts at 216 cfs, peaks at 273 cfs Wed 5 AM (modeled)
Hour	Total (cfs)	Etowah (cfs)	Little River (cfs)	Shoal Creek (cfs)
Tue 12 PM	216	170	42	3.5
Tue 1 PM	217	171	42	3.9
Tue 2 PM	218	172	42	4.2
Tue 3 PM	220	173	42	4.6
Tue 4 PM	222	175	42	5.3
Tue 5 PM	225	177	42	6
Tue 6 PM	230	180	42	7.1
Tue 7 PM	233	184	42	7.4
Tue 8 PM	238	188	43	8.1
Tue 9 PM	243	192	43	8.5
Tue 10 PM	248	196	43	8.8
Tue 11 PM	253	201	43	9.2
Wed 12 AM	257	205	43	9.2
Wed 1 AM	261	209	43	9.2
Wed 2 AM	264	212	43	9.2
Wed 3 AM	268	215	43	9.5
Wed 4 AM	270	218	43	9.5
Wed 5 AM	273	220	43	9.5

EtowahLittle RiverShoal CreekTotal (all gauged reaches)

Dashed lines are forecast. Values are at the gauges; water takes hours to a couple of days to get from there to the lake. Flows are forecast to rise noticeably. National Water Model via NOAA/NWS · public domain.

The “net lake effect” is the forecast inflow volume minus the water leaving the lake now (330 cfs, Etowah at Allatoona Dam, right now), held steady over the forecast period and spread over the lake’s estimated current surface area (before releases it would be +0.03 ft). It ignores travel time, channel losses and any change the dam operators make, so it gives a sense of scale, not a prediction. During floods, watch the main page instead.