So why did this flood happen? Well there have been several previous floods recorded in these same areas. This would be due mainly to the climate, underlying geology, topography, and vegetation. The climate this time of year is general dry but according to Martin Hoerling from Earth System Research Laboratory in Boulder, the moisture-laden air, moving up from Mexico, was drawn up by the mountains thus turning into rain. This event lasted unusually long in the affected area. Now as we all know the topography in the Rocky Mountains is very steep with narrow canyons. The Geology tends to be solid rock, while the vegetation is mainly coniferous trees and alpine plants. Also due to the recent wildfires in some of the effected areas, the newly growing vegetation would be sparse. All of these factors would lead to very small amounts of rainwater being absorbed creating large amounts of surface overflow. The surface flow would quickly drain to the bottoms of the canyons, picking up intensity as it went. This fast-moving water would wash away most anything in its path, creating the damage and devastation in the mountain towns. The water then reached the point where the canyons opened up to the plains. Many cities are located at these points, so while the water slowed somewhat and spread out, it still caused much damage due to the volume and already saturated ground. (Below are a few pictures from The Denver Post showing the damage.)
This flood reminded me of the Rapid City Flood of 1972. So, I wonder what provisions, if any, will Boulder, Longmont, Loveland, and the other affected cities take to keep this kind of damage, destruction, and death from happening again. I felt Rapid City's decision to create the green space along Rapid Creek was instrumental in saving lives and decreasing property damage from future flood events. Below is a flood map of Boulder. Notice the colored areas showing the 100-year and 500-year floodplains. I find it unsettling that the University of Colorado has student housing within the floodplain. So, hopefully better protection against future events will be put into place.
Photo by Joe Amon/The Denver Post
(Floodwater flowing through a housing area and over a road.)
Photo by Tim Rasmussen/The Denver Post
(Notice how the road was no match for the force of the water.)
Photo by Andy Cross/The Denver Post
(The floodwater easily eroded the soft fertile soil.)
Photo by Andy Cross/The Denver Post
(Notice the amount of debris left by flowing water and mudflows, the house is damaged on the left side. US 34 along the Big Thompson River)
Photo by Andy Cross/The Denver Post
(The fast flowing creek washed away the road but was contained by the rock canyon wall. Swollen Big Thompson River damaging US 34.)
Photo by Andy Cross/The Denver Post
(The shear force of the Big Thompson River. This is at Chasteen's Grove waterfall. Loveland's water treatment plant is on the right side of the picture)
Floodplain Map by Oakleafcontracts.com
(Notice where the high school and student housing are located.)
Great post! This was well summarized, and those images are just phenomenal! I really like your comparison with the Rapid City flood, and think it's interesting to contemplate what Colorado might do when it comes to rebuilding and recovery. Turning the floodplain into mostly green areas was a great idea in Rapid but this only works in areas with floodplains, I wonder what could be done in the areas that are in more confined valleys?
ReplyDeleteI really enjoyed the photos. I think the question of what Boulder will do to prevent future flood damage is a question many people will be asking in the next several weeks. What a problem for Colorado.
ReplyDeleteVery well written. Your description of the geology of the area and how this impacted the outcome of the flood was very informative.
ReplyDeleteIt does too remind me of the flood in Rapid City. It is nice that the city put in the green space. It was a smart move on their part. I doubt with the amount of students and limited space that you will find that CU Boulder will do anything about the student housing. Actually at CU Denver campus, the university (way back in the day) forced a Jewish community to leave their house and land because it was sitting in a floodplain, and now their are school buildings their. The only thing left is a very ornate Jewish temple. CU Denver has a special scholarship account set up still for the descendants of these displaced Jewish families who were forced to leave their land under false pretenses.
ReplyDeleteI feel like Colorado will continue to have their work cut out for them for several years to come all along the front range with the amount of massive fires and unusual storms they have been experiencing for several years.
Great images! I did not realize the recent flooding in Colorado was that bad until I saw those images up there. Very enlightening post!
ReplyDeleteI think that the flooding in Colorado was pretty bad. I was interesting in your comment about how they put student housing in the flood plain area. I always say that the only way people will learn is to have something bad happen. They probably knew better than to put it where they did, thinking that nothing bad would happen but that's where they were wrong. They should of been more cautious then they were. But again, you wont learn till you get burnt.
ReplyDelete