Flooding

How to receive flood information:

• BOCO Alert – sign-up at bocoalert.org. By signing-up you’ll receive an alert if the National Weather Service issues a flash flood warning for your area.

• NOAA Weather Radio – weather radios allow you to receive alerts issued by the National Weather Service, and are an essential to stay up on important weather information if you’re out of cell service range. To learn more about how to use a weather radio visit https://boulderodm.gov/preparedness/informed/radio/

• Wireless Emergency Alerts (WEA) – alerts that are sent out for incidents that have an immediate threat to life safety. No sign-up is needed; these “Amber Alert” style alerts go through cell towers to any cell phone in the alerting area that is determined by first responders.

• Outdoor Warning Sirens – located in Central Boulder, South Boulder, Eldorado Springs, Erie, Jamestown, Lafayette, Louisville, Lyons, and Superior, and intended to provide notifications to those who are outdoors. Sirens will broadcast a voice message after the initial siren sound – if you cannot hear the audio message clearly seek additional information at bocoalert.org or at www.boulderodm.gov.

• Emergency Alert System (EAS) – alerts that are broadcast over traditional radio or television for weather related incidents.

• Weather Apps – for weather events that do not rise to the level of flash flood warning or tornado warning use weather apps – many have alerts that they’ll send for heavy rain, thunderstorms, hail, red flag days, etc.

Safety actions:

If you are in an area that is at risk for flooding, is under a flash flood warning, or is starting to flood take the following actions to stay safe.

• Be aware of your surroundings.
  • Before recreating outdoors in areas that are more likely to flood (along rivers, streams, creeks, in canyons, or in low -lying areas) pay attention to the weather forecast.
  • Watch for changes in the color of the water in rivers, streams, and creeks. If you see the water color change (become more cloudy, or have small debris or dirt) move to higher ground immediately. This is a sign that flash flooding is about to occur.
  • If you live, work, or recreate in an area that could flood make sure to pay attention to the weather during heavy rains and take action if flooding is predicted or starting to occur.
• Climb to higher ground – move to a location higher up than your current location.
  • If you’re outdoors, move out of low-lying areas, canyons, or areas near streams/creeks and move to higher ground immediately.
  • If you are indoors, move to a higher floor of the building. If the top floor becomes unsafe, move to the roof and call 911.
• Turn around don’t drown.
  • Do not drive through flood waters. As little as 12 inches can carry away a car, and 18 – 24 inches can carry away a van, SUV, or truck. If your vehicle stalls, abandon it and move to higher ground immediately.
• Stay out of flooded areas.
  • Flood waters are quick moving and contain dangerous types of debris. Do not wade through or play in flood waters – debris like rocks, trees, trash, sewage, chemicals, and power lines all pose potentially life-threatening risks.

BEFORE a flood occurs…

• Create a preparedness plan for your household or workplace. Create a plan using Boulder ODM’s Planning Worksheet.
• Make sure you have flood insurance if you live in a flood plain. The floodplain map for Boulder County and it’s municipalities can be found on the Boulder County Official Regulatory Floodplain Map website.

Boulder Office of Disaster Management’s Role:

The Boulder Office of Disaster Management monitors weather daily using forecasts from the National Weather Service and supplemental weather forecast services (Weather Commander and Mile High Flood Protection District).

When the National Weather Service issues any type of severe weather statement Boulder ODM staff use monitoring tools like radar, rain gauges, and stream gauges to watch for elevated storm escalation, rain runoff, and water amounts in local rivers, streams, and creeks.

When these monitoring tools show signs for potential flooding or severe weather (hail, thunderstorms) information is shared with local response agencies and 911 Communication Centers. Response agency personnel (firefighters, law enforcement, and emergency services personnel) then go out to creeks, streams, canyons, and low-lying areas and monitor water flow, and if a risk to public safety is identified they will request that the 911 Communication Centers send out emergency alerts. Emergency alerts in Boulder County are sent at the request of first responders and are sent by 911 Communication Center dispatch personnel.

In efforts to provide the most proactive approach to weather monitoring ODM staff complete a detailed review of weather forecasts each morning, then review conditions throughout the day to watch for signs of escalation that could result in flooding. Beyond monitoring the tools mentioned above ODM staff members also utilize lightening detection software to be able to predict storm escalation and direction as quickly as possible prior to National Weather Service Warnings being issued. In addition to this analysis, ODM staff review predictive radar software to support early information sharing.

If weather predictions threaten life-safety and property the Emergency Operations Center (EOC) will be activated to provide a real time information sharing center and stand up a coordination structure. The EOC typically activates for flooding concerns when we detect over 1.5 – 2 inches of rain per hour, .75-inch hail, or 50 mph wind.

National Weather Service Flood Terminology

• https://www.weather.gov/mob/severe_flood

Flood WATCH

issued when conditions look favorable for flash flooding. A WATCH usually encompasses several counties. This is the time to start thinking about your plan of action and where you would go if the water begins to rise.

Flash Flood WARNING

issued when dangerous flash flooding is happening or will happen soon. A WARNING is usually a smaller, more specific area. This can be issued due to excessive heavy rain or a dam/levee failure. This is when you must act quickly as flash floods are an imminent threat to you and your family. You may only have seconds to move to higher ground.

Flash Flood EMERGENCY

issued for the EXCEEDINGLY RARE situations when extremely heavy rain is leading to a severe threat to human life and CATASTROPHIC DAMAGE from a flash flood is happening or will happen soon. Typically, emergency officials are reporting LIFE-THREATENING water rises resulting in water rescues/evacuations.