Impact & Continued Risk

Flood Impact

The disaster impact area extends over 200 miles from north to south and includes communities from Pueblo to Fort Collins.  Major statistics include the following:

  • Total rainfall in Boulder County for September 2013 was18.2 inches
    • The average September rainfall for this area is approximately 1.6 inches
    • September 2013 saw twice as much precipitation in one month than any other month in history since recording begin in 1893
    • 486 miles of CDOT roadway were affected at the peak of the flood event, and 39 roadways were temporarily closed
    • 120 CDOT bridges were damaged
    • More than 135,000 cubic yards of debris removed from highways, culverts, and stream channels
    • More than $535 million estimated in state highway and local roadway damage
    • 10 fatalities
    • 18,000 people forced from their homes.
    • 1,882 homes and structures destroyed 16,000 more damaged.
    • More than $304 million in FEMA disaster funds allocated.

Continued Flood Risk

Spring/Summer 2014

The risk of flooding continues to be a major concern to CDOT and local residents, particularly in northern Colorado.  Several factors may contribute to the potential for spring flooding:

  • Mountain areas above flood affected communities have near-record snow pack levels for the 2013/2014 winter season.  Additional snow pack and/or rapid spring warming could accelerate normal snowmelt and runoff, causing increased risk for flooding.
  • Groundwater levels remain very high following the flood event creating an oversaturated ground condition.  This means there is less room for surface water and snowmelt to soak into the soil, so small rain events or rapid snowmelt could trigger flooding more readily than during periods of drier ground conditions.  Additionally, continued oversaturation of the ground could lead to additional debris flow and landslide events.
  • Despite months of intensive debris removal and channel repair, many streams and drainages have reduced carrying capacity due to accumulations of sediment and debris from the 2013 flood event.  Clogged channels may be more susceptible to flooding.
  • Some reservoirs in the area are at or near capacity and may need to spill larger volumes of water than typical during the runoff and thunderstorm season.
  • An El Niño weather pattern, which generally indicates higher than normal moisture, is predicted for 2014.

CDOT emergency managers are on high alert for potential spring flooding.  CDOT recently developed a Flood Recovery Preparedness Plan that will help guide future response efforts.  The plan includes proactive measures such as actively monitoring spring runoff outlooks and weather forecasts.  It also lists identified areas of risk or concern for possible further damage or new damage from the spring runoff or rain events.  For each area of concern, CDOT has documented the potential risk or cause for concern, a method for monitoring the site for the duration of the spring flood season and a response plan in the event that flooding occurs.  The plan also provides contingency strategies for catastrophic events.