Boulder County government offices are closed Wednesday, June 19, in observance of Juneteenth. Primary Elections Vote Center locations are open.

Emergency vehicles driving through floodwaters

Flood Preparation

Boulder County is vulnerable to stream and creek flooding and flash floods. Flooding along streams is a natural and inevitable element of nature. Some floods occur seasonally when spring rains and melting snows fill drainage basins.

Most flash floods are caused by slow-moving thunderstorms or thunderstorms repeatedly moving over the same area. Flash floods are not confined to major drainage ways. Changes to the landscape can increase the risk of flash floods.

Floods can happen with as little as 45 minutes of warning. By understanding the dangers of floods and flooding, property owners at risk can be prepared and save lives.

Preparing Makes Sense:

Take the time now to plan for how you will take care of yourself and your family during a flood or debris flow emergency. You may need to take action before an “official” warning is issued. Planning ahead, can help you:

  • Take steps to minimize the effects of a disaster
  • Reduce fear and anxiety by knowing what to do
  • Be self-sufficient for three to five days, if first responders can’t reach you immediately

Family Emergency Plan:

Learn steps to take for planning before a disaster. These actions can help your family evacuate faster, as well as help family members who may be separated meet at the same location.

Vehicle Safety:

  • Nearly half of all flash flood fatalities are vehicle-related. As little as 18 inches of water can float your vehicle.
  • Never drive your vehicle through flood waters.
  • If your vehicle stalls, leave it immediately and seek higher ground.

If you would like further assistance in emergency planning or if you have any questions, call the Boulder Office of Disaster Management at 303-441-3390 or visit

During a Flash Flood

Learn the steps to take when faced with a potential flash flood, or other flood event.

Landslide Safety

Learn the steps to take when faced with a potential landslide, which may be a result of flooding.

Shelter Locations

In event of evacuations, shelter locations for the affected areas will be available through the Office of Disaster Management website and announced through local media channels.

Emergency Alerts & Warning Systems

The Emergency Notification System (ENS) allows residents of the county and all cities within the county to be notified of an emergency situation in a variety of ways, including on their cell phone, home and work phone and by text message and email. Sign-up at to receive messages about imminent threats and hazards.

The system is free to anyone who lives within Boulder County, including any of the cities or municipalities in the county. Participants are responsible for any fees charged by their provider for text messaging.

Flood Warning and Detection System

A flood forecasting system was implemented after the Big Thompson Flood in 1976. Rain gauges were placed in the drainages emptying into the City of Boulder and throughout Boulder County, west of Highway 36 and below 9000 feet. These gauges are monitored on a 24/7 basis from April through mid-September, peak season for flooding.

Outdoor Warning Sirens

Sirens are an effective way to warn people who are outdoors and in an immediate threat to safety. When you hear a siren, you should:

  • Visit for the latest emergency information.
  • Tune in Boulder Municipal Cable Channel 8 (for those with cable TV in Boulder).
  • Tune in to radio stations KOA 850 AM, KBCO 1190 AM or 97.3 FM.
  • Turn on local television news channels (2, 4, 7, 9 or 31) Listen for a voice message if you are near a voice activated siren.
  • Refrain from calling 911 unless you are experiencing an emergency.

More than 30 outdoor warning sirens are in place across Boulder County. The sirens are located in Boulder, Longmont, Lafayette, Lyons, Eldorado Springs, Jamestown, Superior, Erie and the University of Colorado at Boulder. The outdoor warning sirens are sounded only in the event of an emergency or during pre-announced tests. The sirens are activated through the Boulder County Sheriff’s Communications, Boulder Police and Fire Communications and Longmont Police and Fire Communication centers.

Protect Your Property

When building or rebuilding a home, there are actions that can be taken to minimize risk of damage in future flood events, including elevating the home and floodproofing. The FEMA Homeowner’s Guide has additional information on protecting your home from flooding.