Lake Travis
model 0.2.0 · run 5 hr ago

Lake Travis water level & 10-day forecast

Where the lake is headed.

Lake Travis is at 680.43 ft above mean sea level99.1% of full pool (681.0 ft), 0.57 ft below full.

A physics-driven forecast of Lake Travis water elevation — hour by hour for 36 hours, then daily to ten days — from NOAA river inflows, rainfall over the watershed, evaporation, and dam operations. It grades itself against reality and tunes its own model.

Below full poolupdated 1 hr ago
680.43ft msl
-0.57 ft from full pool · -0.08 ft / 24h
Percent full99%
Storage1,107,275ac-ft
Inflow0cfs
Surface18,970acres

Next 36 hours

hourly · P10 · P50 · P90
680.2680.4680.6680.8681.0681.2Mon 10Tue 11Wed 12full pool 681

hourly · typically within ±0.0–0.2 ft

TimeElevation± band
2 PM680.48±0.00
3 PM680.48±0.00
4 PM680.48±0.00
5 PM680.49±0.01
6 PM680.50±0.01
7 PM680.50±0.01
8 PM680.51±0.01
9 PM680.52±0.01
10 PM680.52±0.02
11 PM680.52±0.02
12 AM680.52±0.02
1 AM680.52±0.02
2 AM680.52±0.02
3 AM680.51±0.03
4 AM680.51±0.03
5 AM680.51±0.03
6 AM680.51±0.03
7 AM680.50±0.03
8 AM680.50±0.04
9 AM680.50±0.04
10 AM680.50±0.04
11 AM680.49±0.04
12 PM680.49±0.05
1 PM680.49±0.05
2 PM680.49±0.05
3 PM680.49±0.05
4 PM680.49±0.05
5 PM680.50±0.06
6 PM680.50±0.06
7 PM680.51±0.06
8 PM680.52±0.06
9 PM680.53±0.06
10 PM680.53±0.07
11 PM680.53±0.07
12 AM680.53±0.07
1 AM680.53±0.07

Why it's moving

now
drivercfsft/day
Inflows +
River inflow
upstream rivers (NWM)
00.000
Rain on lake
direct precip on the pool
00.000
Outflows −
Dam release
normal ops · no floodgates
3000.031
Evaporation
surface loss
2310.024
Net▼ falling
5310.056

River inflow already reflects rain that has fallen across the watershed and rain in the forecast — it's routed downstream into the lake, so “rivers vs. rain” isn't either/or. Rain on lake is only what falls directly on the ~18,981-acre surface.

Floodgates closedLCRA reports no gate operations — the outflow below is normal dam operations (powerhouse + downstream supply), not floodgate spilling.
LCRA · official

Inflows: Inflows to Lake Travis are below levels that would require gate operations to pass floodwaters at Mansfield Dam.

Gate ops: No gate operations to pass floodwaters are expected

Outlook: Please see the <A href="http://hydromet.lcra.org/riverreport/">River Operations Report</A> for current forecasts for Lake Travis.

The lake, live

LT Lake Cam ↗
0 boatsobserved by AI 7 min ago · high confidence
approximate · wide-angle view

Friday morning ski forecast

in 4 days
Friday, Aug 14 · 7 AMglassy — ski it

Glassy enough to shave in.

Wind · 7 AM5 mphgusts 6 · S±4.1 mph typical
Air temp77°F±2.1 °F typical
Water temp86°Fnow 87°F±1.2 °F typical
Lake level680.51′680.32–680.70±0.52 ft typical

graded against 172 past predictions

10-day outlook

daily · P10 · P50 · P90
679.5680.0680.5681.0Wed 12Thu 13Fri 14Sat 15Sun 16Mon 17Tue 18Wed 19Thu 20full pool 681

daily · typically within ±0.2–0.9 ft

DayElevation± band
Wed, Aug 12680.50±0.10
Thu, Aug 13680.51±0.15
Fri, Aug 14680.51±0.20
Sat, Aug 15680.52±0.25
Sun, Aug 16680.46±0.30
Mon, Aug 17680.40±0.35
Tue, Aug 18680.34±0.40
Wed, Aug 19680.29±0.45
Thu, Aug 20680.23±0.50

Recent level history

120 days
full pool 681Apr 12May 6May 30Jun 23Jul 17Aug 10

How accurate is it?

live

How far the forecast typically lands from the real level, by how far ahead it looks.

1 day
typically within ±0.1 ft
90% within ±0.3 ft
5 days
typically within ±0.5 ft
90% within ±1.2 ft
10 days
typically within ±0.9 ft
90% within ±2.9 ft

graded against 77 past forecasts · 120-day window

Each Lake Travis ramp has a published minimum lake level. At 680.43 ft, all 11 ramps with a published minimum are above it. A ramp above its minimum is not automatically open — ramps also close for high water, maintenance and debris.

Lake Travis water level — common questions

What is the current level of Lake Travis?

Lake Travis is at 680.43 feet above mean sea level, about 99.1% of full pool.

Is Lake Travis full?

Not quite — Lake Travis is 0.57 feet below its full (conservation) pool of 681.0 ft above mean sea level.

What is full pool for Lake Travis?

Full (conservation) pool for Lake Travis is 681.0 feet above mean sea level, which is about 1,098,044 acre-feet of storage and roughly 19,000 surface acres. Some third-party sites quote a different datum; 681.0 ft is the LCRA conservation-pool figure.

Is Lake Travis rising or falling?

Lake Travis has fallen 0.08 feet over the past 24 hours.

What is the Lake Travis water level forecast?

Lake Travis is forecast to be about 680.23 feet above mean sea level in 10 days, a change of -0.20 feet from today, with a likely range of 679.73 to 680.73 feet.

When will Lake Travis fill?

Lake Travis is not forecast to reach full pool (681.0 ft) within the next 10 days. Refilling depends on rainfall over the Colorado River watershed upstream, which cannot be predicted reliably beyond about ten days.

How much water is one foot of Lake Travis?

At the current level, one foot of Lake Travis is about 18,970 acre-feet, because the lake covers roughly 18,970 acres. This is not a constant: the surface area shrinks as the lake drops, so a foot near the bottom is worth far less water than a foot near full pool.

How much water does Lake Travis hold right now?

Lake Travis currently holds about 1,107,275 acre-feet of water, roughly 99.1% of its capacity at full pool.

Which Lake Travis boat ramps are usable at the current level?

At 680.43 feet, all 11 Lake Travis boat ramps with a published minimum level are above that minimum. A ramp above its minimum is not guaranteed to be open — ramps also close for high water, maintenance and debris, so check with the operator before towing.

How is the Lake Travis forecast made?

The forecast runs a water balance of the reservoir — river inflow from the NOAA National Water Model, rainfall on the lake, evaporation, and Mansfield Dam release — anchored to the observed 24-hour level trend. Every past forecast is then graded against the measured level, so the published accuracy reflects real performance rather than a claim.

How accurate is the Lake Travis forecast?

Over the most recent grading window, the 24-hour forecast has averaged 0.12 feet of absolute error across 73 graded forecasts. Accuracy for every horizon is published on the site and updated daily.

Why is the Lake Travis water level changing?

Lake Travis rises from inflow on the Colorado River and its tributaries after rain upstream, and falls from LCRA water-supply releases through Mansfield Dam, hydropower generation, downstream demand, and evaporation, which is substantial in a Central Texas summer. Because Lake Travis is a flood-control reservoir, LCRA also draws it down deliberately after major inflow events.

Where does this Lake Travis data come from?

Observed lake levels and floodgate status come from LCRA Hydromet, forecast river inflow from the NOAA National Water Model, rainfall and temperature from the National Weather Service and Open-Meteo, and reference elevation and bathymetry from USGS and the Texas Water Development Board. This site is not affiliated with LCRA; for official flood operations information, consult LCRA directly.

About this forecast

The reservoir

Lake Travis sits on the Colorado River in Travis County, Texas, impounded by Mansfield Dam and operated by the Lower Colorado River Authority. Full (conservation) pool is 681.0 ft above mean sea level — about 1,098,044 acre-feet of storage across roughly 19,000 surface acres. Percent full and feet from full on this site are measured against that datum. Some third-party sites quote a different figure; 681.0 ft is LCRA's conservation-pool elevation.

How it works

The model runs a mass balance of the reservoir — river inflow, direct rainfall, dam release and evaporation — anchored to the observed level trend, and recomputes every six hours. Because change in elevation depends on surface area, which shrinks as the lake drops, it converts storage to elevation through a bathymetric rating table rather than a constant.

Why dam release is an estimate

LCRA does not publish Mansfield Dam discharge, and no external feed carries it. Release here is therefore implied by the mass balance and bounded by LCRA's reported floodgate status: when the floodgates are closed, the outflow shown is normal operations — powerhouse and downstream supply — never floodgate spilling.

Accuracy, published

Every forecast is stored and later graded against the measured level, so the error figures on this page are measured performance rather than a claim. They are updated daily and shown per horizon. Forecasts are estimates, not operational guidance — for official flood information, consult LCRA.

Lake Travis Water Level: 680.43 ft, 99% Full — 10-Day Forecast