After a weekend of rain, flood warnings are in effect for areas near the West and East forks of the San Jacinto River as water from tributaries upstream flows into the Lake Houston area.
The West Fork of the San Jacinto River is predicted to reach an elevation of about 50.9 feet at 3 a.m. Dec. 11 after peaking at 51.8 feet at noon Dec. 8, according to data from the National Weather Service. Moderate flooding along the West Fork begins when the river reaches about 50.3 feet, with major flooding occurring when the river reaches 52.3 feet.
Meanwhile, the East Fork of the San Jacinto River is expected to peak at 64 feet at 9 a.m. Dec. 11, after reaching an elevation of at about 55 feet on Dec. 8 following the rainfall, according to data from the NWS. Moderate flooding occurs on the East Fork when the river reaches 62 feet, with major flooding occurring when the river reaches 69 feet.
NWS Warning Coordination Meteorologist Dan Reilly said moderate flooding conditions usually consist of street flooding, while major flooding conditions can consist of home flooding.
Flood warnings will remain in effect for the Humble area near the West Fork of the San Jacinto River and the New Caney area near the East Fork of the San Jacinto River until late Wednesday, Dec. 12, according to the NWS.
According to a press release Harris County Flood Control District issued Friday, Dec. 7, residents of four neighborhoods along the West Fork of the San Jacinto River and east of Hwy. 59 are expected to experience the worst flooding: Belleau Woods, Forest Cove, North Shore and Riverside Crest.
According to the press release, the river will remain in a flood stage near these neighborhoods until Wednesday.
Reilly said the water elevation of the West and East forks of the San Jacinto River is rising days after the rain as water from creeks and bayous upstream flows into the river. Numerous streams—from as far north as Huntsville—flow into both forks of the river, which then flows into Lake Houston.
Although the water level is expected to increase along both forks of the river, the water level of Lake Houston and Lake Conroe is steadily decreasing.
According to statements from Houston City Council Member Dave Martin’s Facebook page, all gates on the Lake Houston dam are open and will remain open until the lake reaches its normal pool elevation of 42.5 feet. As of 3:30 p.m. Dec. 10, the lake’s elevation was 43.73 feet. The city of Houston began lowering the lake Dec. 7 in preparation of the storm.
Additionally, the San Jacinto River Authority is also continuing to release water from Lake Conroe until it returns to its normal pool elevation of 201 feet. As of 4:11 p.m., Dec. 10, the lake’s elevation was 202.49 feet.