Key Takeaways
- Canyon Lake rose to 81.3 % full by Friday afternoon, July 17, up from 60.9 % full on Tuesday, July 14.
- The increase follows intense rain and flash flooding that drove the Guadalupe and Comal rivers to dangerous heights.
- Although water levels are high, officials warn against immediate recreation because large amounts of debris and sediment lurk beneath the surface.
- Elevated turbidity has triggered a boil‑water notice for dozens of communities that rely on the lake for drinking water.
- Affected areas include Bulverde, Blanco, and numerous subdivisions and ranch developments ringing the lake.
- Water‑quality monitoring is being conducted by the Texas Commission on Environmental Quality (TCEQ), the Water Oriented Recreation District, and the U.S. Army Corps of Engineers.
- Residents should continue boiling water for drinking, cooking, and ice making and avoid lake use until debris is cleared and officials declare it safe.
Recent lake‑level changes
Canyon Lake’s water storage climbed sharply over just a few days. On Tuesday, July 14 the lake stood at 60.9 % full (mean elevation ≈ 891.99 ft). By Thursday, July 16 it had risen to 67.4 % full, and by Friday afternoon, July 17 it reached 81.3 % full, the highest level observed since 2023 and surpassing the post‑July 4, 2025 flood peak. The rapid gain reflects a series of heavy rainstorms that dumped inches of precipitation across the Texas Hill Country, swelling both the Guadalupe and Comal rivers to near‑record flows.
Why officials urge caution despite higher water
The surge in water volume carried a substantial load of debris—tree limbs, trash, sediment, and other material—into the lake. Much of this debris is suspended just below the surface or settled on the lake bottom, making it invisible to casual observers. County officials, the Water Oriented Recreation District, and the U.S. Army Corps of Engineers stress that recreational activities such as boating, swimming, or fishing could encounter hidden hazards that pose injury risks or damage equipment. Consequently, they are asking the public to “hold off a little while longer” until crews can assess and clear the unsafe conditions.
Water‑quality impacts and boil‑water notice
The influx of sediment has heightened turbidity, which can harbor bacteria and microbes that cause gastrointestinal illness (nausea, cramps, diarrhea, headaches). In response, the Texas Commission on Environmental Quality (TCEQ) issued a boil‑water notice effective 8:19 a.m. Thursday, July 17 for all customers drawing water from Canyon Lake. The notice mandates that water be brought to a rolling boil for at least one minute before use for drinking, cooking, brushing teeth, or making ice. The order remains in effect until subsequent testing confirms that turbidity and microbial levels have returned to safe thresholds.
Communities under the boil‑water advisory
The notice covers a broad swath of residents and businesses around the lake. Specifically, it includes the City of Bulverde, the City of Blanco, and numerous subdivisions and developments such as Bulverde Hills, Copper Canyon, Cypress Springs on the Guadalupe, Edgebrooke, Hidden Trails, Hwy 281 North, Lantana Ridge, Oakland Estates, River Crossing, Riverwood Estates, Saddleridge, Singing Hills, Spring Branch Meadows, The Crossing @ Spring Creek, The Woods @ Spring Branch, Canyon Lake Acres, Canyon Lake Island, Canyon Lake Shores, Canyon Ranch, Cascada at Canyon Lake, Canyon Lake Villas, Canyon Lake Vistas, Comal Hills, Cougar Ridge, Deer River, Devils Backbone Heights, Enclave Subdivision, Glenmare, Goldsmith, Hancock Canyon, Hancock Oaks Hills, Hancock, Hillcrest Estates, Lake of the Hills, Lakewood Hills, Mystic Bluff, Mystic Shores, North Lake Estates, Rancho Del Lago West, Rocky Creek Ranch, and several RCM‑managed properties (Cypress Lake at Gardens, Rebecca Creek Estates, Rebecca Creek Park, Springs at Rebecca Creek). Additional areas listed are Scenic Terrace, Serenity Oaks, Stallion Estates, Stallion Springs, Summit North, Tamarack Shores, Tanglewood Shores, The Cedars, The Point, and The Summit at Fischer. In total, more than 40 distinct water‑service zones are affected.
Official response and outlook
Local agencies are coordinating debris removal, sediment monitoring, and water‑testing campaigns. The Water Oriented Recreation District and the U.S. Army Corps of Engineers are deploying teams to survey the lake floor and surface for hazardous materials. While no exact timeline has been given for lifting the boil‑water notice or reopening the lake for recreation, officials emphasize that public safety is the priority and that updates will be issued as conditions improve. Residents are advised to continue following the boil‑water directives, avoid lake‑related activities until cleared, and stay tuned to official channels for the latest information.