Flood Preparation

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.

The area of the Fourmile Fire experienced increased runoff and areas not known for flooding experienced severe flash floods, flood damages, and debris deposition associated with summer thunderstorms.

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

Being prepared also means having access to supplies in case of an emergency. The Boulder OEM website has guidance on making plans and gathering supplies.

Only shelter in place if your home is on high ground and is not in danger from debris flows. Gather supplies to shelter in place:

  • Battery Operated Radio
  • Two Flashlights and Extra Batteries
  • Extra Blankets
  • Non-perishable foods
  • Water (1 gallon per person per day)
  • Important Documents

Family Emergency Plan:

Planning before a disaster can help your family evacuate faster, as well as help family members who may be separated meet at the same location.

  • Have an out-of-state contact for everyone to call and check in. Local phone connections can be unreliable in emergencies.
  • Have at least one, preferably two, safe (higher ground) meeting locations for family members.
  • Practice moving to your safe locations, choose different routes to get there.
  • Make sure family members (and neighbors) know your plans for communication, and the safe meeting 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 Emergency Management at 303-441-3390 or visit www.BoulderOEM.com.

During a Flash Flood

Residents should take the following action in the event of a flash flood:

  • Move to high ground immediately
  • Stay out of floodwaters. Swift-moving water and debris can be deadly
  • Stay away from power lines and electrical wires
  • Leaving the area can pose significant dangers, as road washouts and landslides can occur along escape routes. If you plan to try to leave the area, give yourself as much time as possible, and know that it still may not be enough time (see: Vehicle Safety).

Safety Routes and Locations

  • Plan to go to a safe location. Identify two locations located at higher ground in the case of flooding, and two locations out of the area in case of landslides. Moving to higher ground is not necessarily the best choice in the case of landslides (see: Landslide Safety)
  • Have a plan for your pets so you won’t be delayed in leaving a danger zone
  • Know more than one way to get to your safe locations on foot if necessary (see: Vehicle Safety)
  • NOTE: The City of Boulder may not always be a safe location. City residents may also be affected by flash flooding or water surges in certain situations.
  • Practice leaving by means of your safety routes
  • Talk with family members and neighbors to plan where you will meet and how you will check in with each other at your safety locations

Landslide Safety

Be aware that intense, short bursts of rain may be particularly dangerous, especially after longer periods of heavy rainfall and damp weather. The following steps should be taken in the above situation:

  • Stay alert and awake
  • If you are in areas susceptible to landslides and debris flows, consider leaving if it is safe to do so. If you must remain at home, move to a second story if possible.
  • Listen for any unusual sounds that might indicate moving debris, such as trees cracking or boulders knocking together
  • If you are near a stream or channel, be alert for any sudden increase or decrease in water flow and for a change from clear to muddy water. Such changes may indicate landslide activity upstream, so be prepared to move quickly.
  • Embankments along roadsides are particularly susceptible to landslides. Watch the road for collapsed pavement, mud, fallen rocks, and other indications of possible debris flows if driving (see: Vehicle Safety).

Shelter Locations

In event of evacuations, shelter locations for the affected areas will be available through the Office of Emergency 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 http://www.boco911alert.com 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.

When calling your landline phone, the ENS system generates your phone number to the local public safety agency. If you opt-in to the system for additional notifications, the information you provide will only be used for emergency purposes. It will never be shared with any other organization or used for any other purpose. Your privacy is protected. You do not need to sign up or update information for landline telephones at your home, if your landline is with a company that reports your number for 911 services. Some cable and VoIP providers do not subscribe to the 911 database. To know for certain, inquire with your phone company.

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 www.boulderoem.com 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 sirens will broadcast a voice message immediately following the siren signal to inform the public of the situation and what actions should be taken. When a flood, tornado or other disaster occurs, the sirens will sound. The sound and length of the signal may vary, depending on the situation. Listen for voice commands and tune to a local radio or TV station for further information. (Note: Longmont’s sirens do not include voice commands.) 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 to Retrofitting has additional information on protecting your home from flooding.

Additional Resources

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