percent. From the mouth to a series of falls at 2.1 miles on the south 
fork the gradient averages 0.72 percent. It has two sizeable lakes in 
its watershed; one 85 acres, the other 62 acres in area, Indian and Old 
Tom Creeks are controls and will not be cut; in fact, the Old Tom Creek 
watershed is a Natural Area. 
PRECIPITATION AND AIR TEMPERATURE 
Precipitation is measured at four stations, air temperature at two 
stations. One sea level station is located at Old Tom Creek, Skowl Arn; 
one on the Maybeso Creek watershed at an elevation of 300 feet ;// one 
on the Harris River watershed at an elevation of 100 feet. The fourth 
stations is located at the Hollis headquarters, at sea level (fig. 4). 
Standard non-recording rain gages were used prior to 1953 at all 
stations. Continuous-recording rain gages were installed at Hollis and 
on the Maybeso Creek and Harris River watersheds in 1953. 
Most storms which occur in the study areas appear to be general in 
nature and deposit rain over a relatively large area. This is clearly 
shown by a composite discharge hydrograph for Maybeso Creek, Harris 
River, and Indian Creek (fig. 6). Rainfall is also plotted to show 
relationship between runoff and precipitation. Discharge of these 
three streams rises and falls nearly simultaneously, in minor as well 
as in major variation, indicating that all three adjacent watersheds re- 
ceive precipitation during all, or most, storms which are recorded at 
Hollis. The total amount and intensity of precipitation, however, 
probably varies from watershed to watershed. 
The four climatological stations provide records which are fairly 
representative of conditions on all of the study watersheds. The same 
number and location of stations will be used for the duration of the 
study. Precipitation and temperature records for Hollis and Old Tom 
Creek are shown in tables l(a) and l(b). 
STREAMFLOW 
Rate and characteristics of streamflow influence both the physical and 
the biotic elements of the stream. An increase in rate of discharge may 
have detrimental effects on the spawning facilities of the stream as 
water velocity is a critical factor in the movement of streambed 
material. When water velocity is doubled, its cutting power is in- 
creased about four times, its carrying power is increased about 32 
times. Considerable quantities of gravel may be shifted from one 
position to another, carried downstream, or deposited on dry land when 
flood waters overflow their banks. Movement of stream bed material 
during the period when salmon eggs and fry are present in the stream 
gravels may be detrimental to them. In addition, it may be physically 
impossible for spawning salmon to use otherwise desirable spawning beds 
because of high water velocity. It has been observed during this study 
that in stream sections where velocity is too great, spawning is very 
light or entirely lacking. 
7/ Approximately 25 percent more rain occurs at the 300-foot elevation 
gage on the Maybeso Creek drainage, and 20 percent more at the 100-foot 
elevation gage on Harris River drainage, than falls at the Hollis weather 
station which is located at sea level. 
ii 
