September 18, 1973
TO: WENDALL B. SMITH, CHIEF, HYDROLOGY DEPARTMENT d
FROM: JOSEPH C. HOLZSCHUH, HYDROGEOLOGIST
RE: Average and Maximum Pumping Rates for Given Well Diameters.
As you requested, I have prepared a table of average and maximum pumping
capacities for well diameters from 2 to 24 inches. Please understand
that many assumptions had to be made to prepare this table and the
figures therein may not relate to any given pump installation. Still
I believe that these figures do represent a rough "Ballpark". The
primary assumptions which were made which must be understood are the
1. All rates are pumping rates not average itse rates.
2. Average figures are based on what I believed to be a typical
pumping level for that size well, a typical H. P. rating,
approximately 30 psi. discharge pressure, and with the assumption
that the pump was operated near the peak of its efficiency curve.
3. Maximum figures are based on the maximum amount of water that
a pump, which will fit in the well casing, will deliver assuming
depth to water is 20' (drawdown) and discharge pressure is 0.
This is an optimum situation, not likely to be encountered.
Well Diameter Average Conditions Maximum
2 13 50
3 18 70
4 20 120.
6 500 800
8 550 800
10 700 800
12 1100 1600
14 2400 2900
16 2800 3300
.. 18 4600 5600
20 5000 6900
24 7000 9300