Geology 111 Lab Assignment
Variability in a Local Stream’s Discharge (10 Points)
In this assignment, you will investigate a local stream’s discharge, water height and the area’s rainfall
patterns over a 15-day period from October 25, 2015 to November 10, 2015. Stream measurements are
taken from Little Sugar Creek near the Carolinas Medical Center in Charlotte. Precipitation measurements
are collected at Freedom Park, within a mile of this section of the Little Sugar Creek. Your task is to
answer the questions using the information from the graphs down below, which were acquired from the
USGS Water Resources.
1. What is the approximate “normal” discharge in this creek over this time period? (This is the
average discharge when there are no spikes and the water discharge flattens out). Don’t forget to
give the units and be careful the as the discharge scale is logarithmic. (1 pt)
2. What is the “normal” water height in Little Sugar Creek over this time period? (What is the
height of the water when there are no spikes?) Be sure to include units (1 pt)
3. Portions of the creek flood when the gage height of the water reaches 8.0 ft. Did the creek flood
over this 15 day period? How many times? On what day(s) did the creek flood? What was the
highest peak discharge associated over the 15-day period? Be sure to include units (2 pts)
4. What was the peak discharge reached on October 27th? Be sure to include units. (1 pt)
5. How much cumulative rainfall has occurred in the 15-day period? How many measureable
rainfall events have there been in the 15-day period (These are times of continuous rainfall when
rainfall measurements do not level out)? Which day had the greatest amount of rainfall? How
much rain fell on this day? (Try and estimate to the nearest tenth of an inch) (2 pts)
6. How are periods of peak stream discharge associated with rainfall events? Explain. (1 pt)
7. Little Sugar Creek is in an urbanized area with many streets, sidewalks, parking lots and homes
surrounding it. How would this discharge graph differ if the area were an undeveloped, naturally
vegetated area? Be sure to discuss impervious surfaces, infiltration, groundwater recharge and
flooding. (2 pts)