Inflow forecast

modeled

NOAA’s National Water Model, short-range run issued Sep 29, 10 AM CDT, for the 4 gauged tributary reaches feeding Lake Travis. The model includes rain that has already fallen plus the near-term rain forecast.

Gauged inflow now

201

cfs · measured

Peak next 18h

277

cfs · ~Wed 4 AM CDT · modeled

Projected volume

363

acre-feet over 18h · modeled

Net lake effect

−0.05 ft

after 852 cfs out · inferred

Projected flow by tributary reach

Forecast inflow, next 17 hours, all gauged reaches: starts at 198 cfs, peaks at 277 cfs Wed 4 AM (modeled)
Hour	Total (cfs)	Llano (cfs)	Colorado (cfs)	Pedernales (cfs)	Sandy Creek (cfs)
Tue 11 AM	198	140	53	3.2	1.8
Tue 12 PM	201	141	54	3.5	1.8
Tue 1 PM	205	142	57	3.9	1.8
Tue 2 PM	209	144	59	4.2	1.8
Tue 3 PM	215	146	63	4.9	1.8
Tue 4 PM	223	147	68	6	1.8
Tue 5 PM	231	149	74	6.7	1.8
Tue 6 PM	240	150	80	7.4	1.8
Tue 7 PM	247	151	87	8.1	1.8
Tue 8 PM	254	152	92	8.5	1.8
Tue 9 PM	260	152	98	8.8	1.8
Tue 10 PM	265	152	102	9.2	1.8
Tue 11 PM	268	152	105	9.2	1.8
Wed 12 AM	271	152	108	9.2	1.8
Wed 1 AM	274	152	110	9.5	1.8
Wed 2 AM	275	152	112	9.5	1.8
Wed 3 AM	276	152	113	9.5	1.8
Wed 4 AM	277	152	113	9.5	1.8

LlanoColoradoPedernalesSandy 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 (852 cfs, Mansfield Dam, yesterday's average), held steady over the forecast period and spread over today’s surveyed surface area (TWDB) (before releases it would be +0.02 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.