The USGS gauge is approximately 30 miles upstream. At times of rapid waterlevel change, there is approximately a 20 hour delay from the level at Riverton to this playspot in Petersburg.
The drainage area at Petersburg is 3,063 square miles, whereas the drainage at the gauge in Riverton is 2,618 square miles. Thus, one might expect (on average) the actual flow at this playspot to be 1.17 times (or 1 and 1/6th as much as) the flow on the cited gauge.
Gauge/flow analysis based on Riverton gauge 1908 to 2008:
Minimum mean daily flow during stated period: 3 cfs (1914.10)
90% of time flow exceeds: 84 cfs
10% of time flow exceeds: 3,490 cfs
Maximum mean daily flow during stated period: 67,700 cfs (1943.05.19)
10/90 ratio ('flashy-ness'): 41.5 (under 3 is fairly steady, over 10 is quite 'flashy')
Average days per year over recommended 'low' threshold (75 cfs): 223
|SANGAMON RIVER AT RIVERTON, IL|
|usgs-05576500||3000 - 4000 cfs||III+||01h21m||~ 4990 cfs (too high)|
|Very high flow. (~12.25' - 18.3')|
Gauge (2618 sq.mi. drainage) is well upstream. At Petersburg (3063 sq.mi. drainage) flows may be ~1/6th again as high (I.E. 1.17*gauge).
Reports give the public a chance to report on river conditions throughout the country as well as log the history of a river.
|Sangamon [IL]||Beginner's first surf||300||clinton begley|
|Sangamon River [IL]||Throwing ends in Dead Carp Drop||2500 cfs||Erik Johnson|
|> 10 years||sangamon [il]||Clint at dead carp drop||435 cfs||clinton begley|
|> 10 years||Sangamon River [IL]||Perfect level @ DCD||9 feet||Erik Johnson|
|> 10 years||Sangamon River [IL]||n/a||Jeff Abernathy|