has a unique environmental situation, primarily due to the proximity
to the Rocky Mountains and the occurance of daily afternoon thunderstorms
during the summer months. These thunderstorms, sometimes quite
severe, have the ability to create flash flood situations. Additionally,
the majority of downtown Boulder lies in the flood plain of Boulder
Creek. The construction of a dam, 15 miles upriver of Boulder
has provided some flood control, however the threat for a massive
100 year flood is still a reality.
Signs like this one warn Boulderites of the ever present threat
of flash floods.