Shedding light on sedimentation
Kyle Juracek, a research hydrologist for the USGS discussed sedimentation in Kansas reservoirs and provided sediment-related data during our class today.
"A reservoir is a reflection of what is happening upstream, " Juracek said. Which is why it's important to look at sedimentation rates in our Kansas watersheds.
Sedimentation is, "the deposit of silt, soil, clay and/or sand in locations where slow-moving water loses its ability hold heavier particles in suspension" (according to the Layman's Guide to Kansas' Water Terminology & Acronyms).
Once a sediment pool is full, additional sediment will begin filling in a water supply. Some of the numbers Juracek presented really surprised me. For example, according to an estimate for 2005, Tuttle Creek in Manhattan could have around 142,000 acre-feet of sediment. That's more than 292 million lbs! Sediment is heavy. Literally.
When the Army Corp of Engineers designed reservoirs for Kansas, they predicted how long it would take for sedimentation pools to fill. Clinton Lake's design life was 100 years. To be clear, that doesn't mean that Clinton Lake will fill up with sediment by 2080, it just means the engineers estimated that the sedimentation pool would be full by then. One estimate (based on 1991 figures) projected that by 2005 6 percent of Clinton's storage capacity would be lost due to sedimentation.
If you want to learn more about reservoir design, there is a detailed explanation complete with some scary looking engineering algebraic formulas (Courtesy the Texas Department of Transportation).