Level of the Lake

Rivers into Lake Buchanan

48 cfs flowing in right now from the gauged river. Tap a river for its gauge page.

Where the water is flowing

Swipe sideways to follow the river to the lake →

48 cfs48 cfsColorado48 cfsLake BuchananColorado incl. San Saba Riv…96% fullBuchanan storage
SteadyReceding · high water draining downOn the rise · climbing right nowInbound wave · big rise upstreamFlooding · NWS, by river heightNo current readingRising or falling is judged from each gauge’s last 48 hours, scaled to its river. Dot speed follows the flow. NWS flood status comes from river height and outranks direction.

Streamflow at the river gauge (USGS or LCRA, whichever is newer). Labels are gauge readings in cfs. Line width isn’t to scale.

The rivers, gauge by gauge

48cfs combined

Gauged rivers only. Runoff below these gauges and ungauged arms aren’t counted. Streamflow: USGS or LCRA Hydromet, whichever reported last for each gauge (provisional). Flood status: NOAA/NWS, from river height at each gauge rather than flow.

Rain outlook

modeled

About 0.72 in forecast over the next 3 days, averaged across the basin, heaviest in the Lake area basin (1.09 in).

Open-Meteo model forecast for each basin that drains to the lake.

Last 24 hours at the rain gauges →Radar map →River inflow forecast →
How we know thisToday’s water budget: what came in and what went out

Up or down? Down 0.17 ft over the last 7 days (LCRA lake level).

Where the water came from and where it went, at today’s rates. Dam releases and withdrawals have no complete public feed, so they land in the leftover line, which is inferred from the other lines.

  • River inflowmeasured
    +95 af/day≈ +0.05 in/day on the lake

    LCRA gauge, at current rates

  • Evaporationmodeled
    −399 af/day≈ −0.22 in/day on the lake

    Estimate from long-term averages over 22,113 surveyed acres (TWDB)

  • Everything leaving that we can’t meter (releases, withdrawals)inferred
    −233 af/day≈ −0.13 in/day on the lake

    What’s left once the other rows and the storage change are counted

  • =Storage changeinferred
    −537 af/day≈ −0.29 in/day on the lake

    The lake's level change over the last 7 days (−0.17 ft, LCRA), as a daily average, × 22,113 surveyed acres (TWDB)

The lines above add up to the storage change: what the lake gained or lost. Inflow is current; storage is the average over the last 7 days, so the leftover also absorbs any change in pace over that time.

That leftover is about 117 cfs leaving the lake, mostly dam releases and withdrawals, plus whatever the upstream gauges missed.

Where it’s going

  • Evaporationmodeled

    estimate from long-term averages

    399 af/day≈ 201 cfs
  • Withdrawals and other unmetered waterinferred

    the leftover from the budget above

    233 af/day≈ 117 cfs

No public gauge measures water leaving through the dam, so releases are counted in the leftover. The withdrawals line is the budget’s leftover: city intakes, ungauged runoff and estimation error. The lines can overlap, so treat the split as approximate.

How this is computed

Inflow converts current streamflow at the gauged tributaries (LCRA) to acre-feet per day (1 cfs ≈ 1.9835 af/day). Evaporation uses long-term monthly averages for the region over today’s lake surface. That surface area is TWDB’s daily survey where published, otherwise estimated from storage. With no storage reading, evaporation isn’t estimated. Inches on the lake divides each volume by that same surface area, so an inch takes less water when the lake is low and narrow than when it’s full and wide. Storage change is the lake’s level change (LCRA) times that surface area, averaged per day over the last day for a once-a-day feed, otherwise over the last seven days. The leftover is what it takes to make the lines add up. It lumps together dam releases, withdrawals, and ungauged runoff, which can’t be split without data the operator doesn’t publish.

All inputs are provisional. This page is an estimate, not an official accounting.

The water budget on its own page →