About Medina Lake Live

What this site shows, and how the numbers are worked out

Medina Lake Live is a simple dashboard for Medina Lake in Medina County, Texas. It pulls public gauge data every 60 seconds and reduces it to the numbers people actually care about: how full the lake is, whether it's rising or falling, and whether flooding is a concern upstream.

Where the data comes from

All readings come directly from two public government APIs — nothing is hand-entered:

• USGS Water Services (site 08179500 for the lake, plus three upstream river gauges) provides elevation, storage, and streamflow.
• NOAA's National Water Prediction Service (gauge MDLT2) provides the official flood-category status.

Both sources are provisional and subject to revision by USGS/NOAA. The underlying gauges sample roughly every 15 minutes and transmit hourly-ish, so the "as of" time on the page reflects the true reading time, not when the page happened to poll.

Percent full

Calculated as current lake storage (acre-feet) divided by conservation capacity, 254,823 acre-feet — the storage volume at the top of the conservation pool. This is the standard way reservoir operators express "how full" a lake is.

Flood status

Pulled directly from NOAA's official flood category for the lake (no flooding / minor / moderate / major) rather than calculated independently, since NOAA's thresholds already account for local flood-stage criteria.

Spillway distance

The difference between current lake elevation and the spillway elevation, 1,064.20 ft. When elevation exceeds this, the lake is spilling.

Why three upstream gauges, and why they're never summed

English Crossing, Bandera, and Patterson Rd all sit on the same Medina River channel, one after another moving downstream toward the lake — they are not separate tributaries. Summing their flows would double- and triple-count the same water. Instead, English Crossing (the furthest downstream of the three) is used alone as the lake-inflow estimate, while Bandera and Patterson Rd are shown as earlier read on the same river for context on what's headed downstream.

Who runs this

Medina Lake Live is an independent, non-commercial hobby project — not affiliated with USGS, NOAA, or any government agency. See the Privacy Policy for details on analytics and cookies, or the Contact page to get in touch.