Otter Creek had an average annual discharge at the gaging station of 22 cfs (cubic feet per second) or 15,900 acre-feet per year from a drainage area of 132 square miles during a selected 19-year base period, water-years 1938-56.
The maximum yearly runoff was 43,410 acre-feet for water-year 1957. The maximum monthly runoff was 24,090 acre-feet in May 1957.
Otter Creek has extended periods of no flow except for about the last 5 miles near the mouth. The most severe droughts occurred in 1938-41 and 1952-56. Periods of no flow have extended as long as 363 days and have exceeded 300 days many times.
The usable storage required to provide a regulated discharge equal to about half the average discharge at the gaging station at Snyder Lake during the most deficient period was determined to be 18,000 acre-feet.
Miscellaneous measurements made at selected sites show that there is no sustained base flow in any of the tributaries and none in the mainstem except for about the last 5 miles near the mouth. A group of measurements made in September 1961, when there was ground-water outflow in all of the main tributaries except Horse Creek, shows that most of the ground-water outflow in the upper part of the basin comes from the tributaries that originate in the Wichita Mountains. Considerable base runoff occurs in the lower part of the basin from large alluvial and terrace deposits.
(available as photostat copy only)