Essay on Water Resources
ANSWER THE FOLLOWING QUESTIONS IN WRITING ABOUT EACH TOUR STOP:
1) The Missouri River Levees R-613 and R-616 located south of Bellevue, NE along the Missouri River, Papillion Creek, and Platte River were built at different times in 1975 and in 1986. Improvements are now underway to increase the height of the R-613 levees. Additional work to improve the levees requires the construction of new seepage berms, the improvement of each culvert through the levees, and the installation or rehab of gates that can open or close these culverts which pass through the levee. Review the information in the handouts and from class. Why were the R-613 levees built in 1975 not constructed as high as the R-616 levees built in 1986?
The R-613 levees in 1975 were not constructed as high as the R-616 levees because the R-613 were not effective enough in preventing flood overflows to the surrounding areas. Therefore, constructing R-616 levees higher than R-613 increases the effectiveness by preventing flood flows from overtopping the levees.
2) Schramm State Rec Area includes the land that was home to Nebraska’s first state-run fish hatchery (known as the Gretna Fish Hatchery). Looking at the geologic layers in the handouts, what layer at the top of the outcropping is likely the same geologic layer that the spring comes from in the canyon ponds located directly north (upstream) of the hatchery ponds?
The limestone layer at the south bend of the outcropping part is similar to the layer from which the spring comes.
3) The Western Sarpy Levee stretches for 6 miles along the Platte River west and south of Gretna. The 2019 Flood reached approximately 215,000 cfs at Ashland USGS gage, how much flow was the Western Sarpy Levee designed to protect from?
The project for the reconstruction of the Western Sarpy Levee was designed to protect up to 151000 cfs of open water.
4) Stop 4 is part of a prairie preserve owned by UNO called the T.L. Davis Preserve. Between the edge of the preserve and the 245th Street roadway is a geologic outcrop of Dakota Sandstone. Being higher in elevation, there is no limestone or shale layers visible at this location. Since the Dakota formation was formed nearly 100 MYA during the early cretaceous, these sandstone deposits were part of the shifting shoreline of what ancient seaway?
The sandstone deposits were part of the Western Interior Seaway (University of Nebraska-Lincoln, 2020). The formation of the Dakota Sandstone took place in the Mesozoic era.
5) The MUD West Water Treatment Plant was completed and operational in 2008. Raw water is pumped out of the groundwater along both sides of the Platte River, just southwest of 264th Street and Q Street. An area directly surrounding the wells is considered a Wellhead Protection Area and can be seen on the Google Earth file provided for this assignment. MUD has a Wellhead Protection Area plan that can be viewed here. From the wells, water is pumped over 4 miles all the way along Q Street into the new treatment plant where it is filtered, lime softened and disinfected (and then sent out in pipes to everyone’s homes and businesses). See pictures from our tour last year in the handouts. See “Triangle of Reliability” brochure saved in “Virtual Tour” folder. What was the total approximate cost of the entire project?
The MUD West Water Treatment Plant project was approximately 352 million dollars.
6) The Zorinsky Water Quality Basin #1 (ZB1) was completed in 2015 and is part of the Watershed Management Plan for Zorinsky Lake and has the primary goal of trapping sediment and pollutants before the flow into Zorinsky Lake. See Hydraulic Design Data table attached with the handouts. What percent reduction in peak flow occurs during the 100-year design storm event at this Water Quality Basin weir?
The ZB1 has a 30 percent peak flow reduction.
7) Flanagan Lake is a Regional Detention Basin (dam) constructed as part of the Papillion Creek Watershed Management Plan for the Papillion Creek Watershed Partnership. Originally known as Papio Dam Site 15A, this lake has a drainage basin of nearly 11 sq miles. See Hydraulic Design Data table attached with the handouts. What percent reduction in peak flow occurs during the 100-year design storm event at this dam?
The Flanagan Lake dam has a 98 percent peak flow reduction.
8) Similarly, Prairie Queen Recreation Area and lake was completed in 2015 as part of the Papillion Creek Watershed Management Plan. Originally known as Papio Dam Site WP5, this lake has a drainage area of just over 5 sq miles. See Hydraulic Design Data table attached with the handouts. How is the percent reduction in peak flow during the 100-year design storm event different at this regional detention basin than at ZB1?
The peak flow reduction of the Prairie Queen Recreation Area in 100-year design storm event is 97 percent. The difference between the peak flows is that the water flow in the Prairies Queen Recreation Area at 3.3% has a low chance of reaching the peak in 100 years. (United States Geological Survey, 2020). The percent of peak flow in ZB1 has a 30 percent reduction, which is lower than Prairie Queen Recreation Area, hence a higher chance (70%) of reaching the peak in 100 years.
References
United States Geological Survey. (2020). The 100-Year Flood. Retrieved from https://www.usgs.gov/special-topic/water-science-school/science/100-year-flood?qt-science_center_objects=0#qt-science_center_objects.
University of Nebraska-Lincoln. (2020). Nebraska during the cretaceous. Retrieved from http://eas2.unl.edu/~tfrank/History%20on%20the%20Rocks/Nebraska%20Geology/Cretaceous%20Webpage/Nebraska%20In%20Mesozoic/Nebraska%20in%20the%20Cretaceous.html.
