Harris County Flood Control District Monitoring Heavy Rainfall Potential from Tropical Storm Nicholas

The Harris County Flood Control District is actively monitoring tropical storm Nicholas which formed in the southwestern Gulf of Mexico and poses a heavy rainfall and flood threat to our area this week.

Extremely heavy rainfall is expected through Wednesday. Widespread totals of 4-8 inches are expected but in isolated areas. Those south of I-10 could receive as much as 12 inches or more of rainfall through Wednesday and will likely result in street flooding and rapid rises on area bayous and creeks. Some flooding of bayous and creeks will be possible depending on the intensity and longevity of the rainfall. Currently, Addicks and Barker reservoirs are empty and have maximum storage capability ahead of Tropical Storm Nicholas.  

  • Coastal counties: widespread 10-15 inches (isolated areas 20 inches).
  • South/East of US 59: widespread 8-12 inches (isolated areas 15 inches).
  • North of I-10: widespread 4-6 inches (isolated areas 8 inches).
  • Flash Flood Watch is in effect for areas along and SE of US 59.
  • Storm surge values of 3-5 feet from Port O Connor to Sargent and 2-4 feet from Sargent to High Island including Galveston Bay above normal dry ground.

Tropical storm force winds of 40-50 mph are possible in coastal southeast Harris County with gusty winds of 30-40 mph across the remainder of the county.  The Harris County Flood Control District flood operations team is actively monitoring conditions and coordinating with partner agencies. Flood Control District staff will continue to monitor rainfall trends and check gages that measure rainfall amounts and water levels in bayous and creeks and coordinate with local, regional, and federal partners on the response and forecast of both heavy rainfall and potential flooding.

Harris County residents are urged to monitor weather conditions as well as creek and bayou levels into the weekend. Heavy rainfall could quickly overwhelm storm sewers and roadside ditches resulting in street flooding. The Flood Control District encourages residents to take the following precautions when heavy rainfall and potential flooding is expected: 

  • Create an account and sign up for rainfall and water level alerts at FWS Alerts allow residents to customize the sensors they receive alerts from and choose to receive them via text, email, or both.  
  • Make sure storm drains and culverts are clear from debris. Clogged drains and culverts can prevent water from traveling to the bayous and tributaries, causing street flooding, and possible house flooding, depending on the amount of rain we receive.
  • Move vehicles to driveways or in parking garages as the storm approaches in areas that normally experience flooding. 
  • Move emergency supplies and valuables to a high, dry place in your residence.
  • Never drive into high water. Turn Around, Don’t Drown! Less than two feet of water can float and wash away a vehicle. Be especially cautious at underpasses and at night when water across roadways can be difficult to see.
  • Refrain from discarding debris in areas bayous, streams and ditches. Debris should be put in trash bins and then brought inside into garages or backyards, away from drainage ditches and storm sewers.
  • View the Harris County Office of Homeland Security and Emergency Management disaster preparedness resources at
  • Carry flood insurance. Residents should contact their insurance agent for more information about purchasing flood insurance or visit the National Flood Insurance Program or call 1-888-379-9531. Please keep in mind that new insurance policies take 30 days to go into effect.