WATER RESOURCES OF ORANGE COUNTY 71
The flow of Rock Springs, Wekiva Springs, and Witherington Spring (stations 56, 61, and 62) near Apopka in the Wekiva River basin have been measured occasionally since 1931. Table 11 shows the results of these measurements.
The average flow from Wekiva Springs is estimated to be 74 cfs and from Rock Springs, 60 cfs. Curves 7 and 8 (figure 15) show flow-duration for Wekiva Springs and Rock Springs, respectively. The extremely flat slope of these curves is due to the small variation in flow characteristic of ground-water sources.
The quality of water from Rock and Wekiva Springs is similar to that of the ground water in the area, and it varies only slightly with flow. Table 8 gives ranges of dissolved constituents and properties of the water in Rock and Wekiva Springs.
Apopka-Beauclair Canal
This canal drains Lake Apopka and the surrounding areas. The total area drained by the canal is about 180 square miles, of which about 120 square miles is in Orange County. Altitudes in this basin range from about 65 feet in the mucklands adjacent to Lake Apopka to 225 feet near Lake Avalon.
The flow in Apopka-Beauclair canal near Astatula was measured periodically at station 3 from 1942 to 1948. Since July 1958 the daily flow has been determined at station 4. During the period of record, the maximum flow at station 4 was 754 cfs in March 1960 and the minimum flow was estimated to be about 1 cfs during periods when a control structure in the canal was closed. The average flow at station 4 during the period 1958-63 was 118 cfs. Flow-duration curves and flow-frequency curves have no significance at this station because of the artificial regulation of the flow; therefore none are given.
The quality of the water in Apopka-Beauclair canal is similar to that in Lake Apopka. The water quality of Lake Apopka is discussed under the following section on lakes, swamps, and marshes:
LAKES
OCCURRENCE
Orange County has about 1,100 permanent bodies of open water ranging from small water-filled sinks to widenings of stream