[Pre- and post-dam period of records are in water years. Recurrence intervals for the small and large floods are 2 and 10 years, respectively, and based on daily mean, not annual peak streamflow data]
| |
Pre-dam
1936–1962 |
Post-dam
1963–2008 |
Percentage
change |
| Reach 1 below Trail Bridge Dam at McKenzie River near Belknap Springs (14158850) |
| Number of years in period |
27 |
46 |
|
| Percent streamflow exceedance, in cubic feet per second |
| 10th |
1,520 |
1,509 |
-0.7 |
| 50th |
884 |
916 |
3.6 |
| 90th |
601 |
622 |
3.5 |
| 10th/50th |
1.72 |
1.65 |
-4.2 |
| Median Julian date of the annual minimum daily streamflow |
281 |
284 |
|
| Percent of years having one or more small floods per year |
44 |
37 |
-17 |
| Percent of years having two or more small floods per year |
15 |
2.2 |
-85 |
| Percent of years having one or more large floods per year |
7.4 |
2.2 |
-71 |
| Median of the large-flood magnitudes, in cubic feet per second |
6,540 |
7,650 |
17 |
| Reach 3 below Cougar Dam at South Fork McKenzie River, near Rainbow (14159500) |
| Number of years in period |
28 |
45 |
| Percent streamflow exceedance, in cubic feet per second |
| 10th |
1,700 |
1,430 |
-16 |
| 50th |
604 |
705 |
17 |
| 90th |
235 |
277 |
18 |
| 10th/50th |
2.81 |
2.03 |
-28 |
| Median Julian date of the annual minimum daily streamflow |
275 |
64 |
|
| Percent of years having one or more small floods per year |
46 |
4.4 |
-90 |
| Percent of years having two or more small floods per year |
7.1 |
.0 |
-100 |
| Percent of years having one or more large floods per year |
7.1 |
.0 |
-100 |
| Median of the large-flood magnitudes, in cubic feet per second |
13,950 |
0 |
-100 |
| Reach 5 below Blue River Dam, at Blue River, near Blue River (14162200) |
| Number of years in period |
33 |
40 |
| Percent streamflow exceedance, in cubic feet per second |
| 10th |
1,044 |
1,006 |
-3.6 |
| 50th |
256 |
294 |
15 |
| 90th |
32 |
51 |
59 |
| 10th/50th |
4.08 |
3.42 |
-16 |
| Median Julian date of the annual minimum daily streamflow |
271 |
52.5 |
|
| Percent of years having one or more small floods per year |
45 |
0 |
-100 |
| Percent of years having two or more small floods per year |
12 |
0 |
-100 |
| Percent of years having one or more large floods per year |
9.1 |
0 |
-100 |
| Median of the large-flood magnitudes, in cubic feet per second |
12,690 |
0 |
-100 |
| Reach 7 at McKenzie River near Vida (14162500) |
| Number of years in period |
39 |
46 |
| Percent streamflow exceedance, in cubic feet per second |
| 10th |
7,000 |
6,970 |
-0.4 |
| 50th |
3,030 |
3,230 |
6.6 |
| 90th |
1,600 |
2,167 |
35 |
| 10th/50th |
2.31 |
2.16 |
-6.6 |
| Median Julian date of the annual minimum daily streamflow |
276 |
282 |
|
| Percent of years having one or more small floods per year |
44 |
2.2 |
-95 |
| Percent of years having two or more small floods per year |
13 |
0.0 |
-100 |
| Percent of years having one or more large floods per year |
7.7 |
2.2 |
-72 |
| Median of the large-flood magnitudes, in cubic feet per second |
47,900 |
43,200 |
-10 |
| Reach 12 at McKenzie River near Coburg (14165500) |
| Number of years in period |
27 |
46 |
| Percent streamflow exceedance, in cubic feet per second |
| 10th |
10,500 |
9,860 |
-6.1 |
| 50th |
4,304 |
4,096 |
-4.8 |
| 90th |
1,820 |
2,390 |
31 |
| 10th/50th |
2.44 |
2.41 |
-1.3 |
| Median Julian date of the annual minimum daily streamflow |
274 |
259 |
|
| Percent of years having one or more small floods per year |
44 |
11 |
-76 |
| Percent of years having two or more small floods per year |
15 |
0 |
-100 |
| Percent of years having one or more large floods per year |
7.4 |
2.2 |
-71 |
| Median of the large-flood magnitudes, in cubic feet per second |
67,400 |
83,100 |
23 |
U.S. Department of the Interior | U.S. Geological Survey