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Colorado Floods Q & A
09/19/2013 01:29PM

Colorado Flood Q&A

The Colorado floods that devastated much of the Front Range over the past week has been on our minds, as we are sure it's been on yours. We at the Colorado Watershed Assembly have been thinking about all those affected by the torrential rains and destructive flooding that occurred, and our hearts go out to you.

With the floods fresh on our minds, we wanted to answer the questions we've heard some of you asking about the flood in general or how it might affect our River Watch program. The questions answered below, by our resident experts, are just a start. If you have more questions you would like answered, please feel free to leave them in the comments section!

Question: Generally speaking, how will the recent flood events affect water quality in the short term?
Answer: The flood waters will affect water quality in the short term with higher values of TSS (Total Suspended Solids) and hardness spiking dramatically.  A very basic definition of TSS is the amount of particulates in the water. This is going to rise due to sediment and debris being washed down the river. Hardness will increase because soil sediment in the river floating downstream contain calcium and magnesium which drives up hardness values (think divalent cations in the water increasing). This flood water contains a significant higher amount of minerals. Temperature will increase due to increased solar radiation absorption (darker water) and shallow standing or slow moving waters. There could a temporary decrease of macroinverebrates due to habitat loss, sediment and silt accumulation. 
 
There is also an increased threat of tetanus infection due to waters being contaiminated with human and animal fecal matter. Please stay out of the water.   - Answered by Matt McIntyre, River Watch Water Quality Analyst

Question: How will this flood event affect overall water quality?
Answer: The flood event will affect water quality over all and in general. It may or may not help, but it is good to know that just like fires, floods are natural and very necessary for the heath of forests, rivers and upland riparian zones. In the long term, it also benefits animals and plants. Of course, as humans we don't like the damage and harm to property, injuries and death, but speaking from an ecosystem perspective floods are essential for river health. The fact that many of our rivers are sick is because the flood cycle has been taken out of the calendar. Floods scour out bottoms, move nutrients and debris down stream onto flood plains, providing needed food and nutrients, thus re-energizing the connection between the river and the flood plain. One example of how this benefits the river is the cleansing of the river bottom allows for new habitat to be formed and created from settled in sediment. - Answered by Barn Horn, CPW Water Resource Specialist

Question: What will this mean for River Watch?
Answer: RW's study design is to answer large scale questions, not specific questions such as is the discharge polluting, etc. but the overall health of a river between, during, and after events such as floods, fires, and all human impacts on a geologic scale, not an emergency response scale. The type of monitoring done to protect the public from health issues (locations, frequencies, indicators and such) is not what RW is qualified to do or sets out to do. That is under the local and state health departments who are in theory equipped to monitor this, because they have knowledge and access to do that, in a way our volunteers and networks are not, simply because it is not our role. River Watch will like see the impacts of these events in the long term. As with the fires, perhaps not as severe as one might think---as again these systems evolve with these events. We forget to look at the big picture, the ecosystem succession time scales which are longer than our lives. This provides a different perspective, one that is contrary to our human desire to not want to see things change. - Answered by Barn Horn, CPW Water Resource Specialist

Question: The river my sample site is on is flooded. When should I go and take my next sample?
Answer: We're sorry to hear the flood affected you, but hope you're safe. Our number one priority is volunteer safety during a sampling event. Please simply sample again when the waters are low enough that it's safe for you to do so. This will be different for each group, depending on the severity of flooding at the station. You can check with local authorities to make sure the threat of contamination is minimal and there are no safety concerns in regards to you getting to your site and getting in the water. While the information you get from your next sample would be useful in a way that it might be interesting to see what's going on due to the flood event, these samples would likely be outliers in the data and have the potential to be put aside regardless. Err on the side of caution and stay safe! - Michaela Taylor, River Watch Program Manager

For more information on how you can help with flood relief efforts, go to www.helpcoloradonow.org. Please leave any other questions you have in the comments or email riverwatch@coloradowatershed.org!

 


 
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