Streamflow
On average, the dry-season flow of San Diego Creek is partially if not entirely composed of urban runoff, agricultural runoff and other human-induced sources. According to the United States Environmental Protection Agency, average dry-season flow at the mouth is 8 to 15 cubic feet per second (0.23 to 0.42 m3/s), whereas wet-season runoff can range from 800 to 9,000 cubic feet per second (23 to 250 m3/s). The average annual flow is about 61 cubic feet per second (1.7 m3/s), 44,200 acre feet (0.0545 km3) per year. An all-time highest flow of 43,500 cubic feet per second (1,230 m3/s) was recorded on December 6, 1997.
The peak streamflow data collected by the United States Geological Survey at Campus Drive (near the mouth), with five recorded peaks, is given in the below table:
| Year | Streamflow (cfs and m3/s) |
|---|---|
| 1978 | 9,080 cubic feet per second (257 m3/s) |
| 1979 | 6,400 cubic feet per second (180 m3/s) |
| 1983 | 15,500 cubic feet per second (440 m3/s) |
| 1984 | 7,100 cubic feet per second (200 m3/s) |
| 1985 | 3,040 cubic feet per second (86 m3/s) |
At Culver Drive, near the Irvine city center, 32 peaks were recorded. The largest five flows are given, in ascending order:
| Year | Streamflow (cfs and m3/s) |
|---|---|
| 1952 | 4,040 cubic feet per second (114 m3/s) |
| 1979 | 5,550 cubic feet per second (157 m3/s) |
| 1978 | 6,300 cubic feet per second (180 m3/s) |
| 1969 | 6,700 cubic feet per second (190 m3/s) |
| 1983 | 10,400 cubic feet per second (290 m3/s) |
At Lane Road, which is well upstream of Culver Drive several miles below the headwaters of San Diego Creek, only three peaks were recorded:
| Year | Streamflow (cfs and m3/s) |
|---|---|
| 1974 | 2,360 cubic feet per second (67 m3/s) |
| 1975 | 4,000 cubic feet per second (110 m3/s) |
| 1976 | 1,035 cubic feet per second (29.3 m3/s) |
Read more about this topic: San Diego Creek