SECTION OF IRRIGATION AND METEOROLOGY. 
7 
The Rocky Ridge reservoir is situated several miles farther 
north, on the east side of the Larimer County Canal, which here 
passes on a ridge on the west and south side of the lake. To the 
east of the lake is a cliff of sandstone several hundred feet high. 
The outlet of the reservoir* is by a short tunnel under the canal, 
through a ridge to the west of the lake. The reservoir was being 
filled during the second winter of observation, so that a record was 
not taken. 
The North Poudre Canal reservoirs^, of which three were observed 
in the winter of 1895-6 and four in the winter of 1896-7, are 
natural basins, most of which have an embankment thrown up on 
one side. These lakes are of considerable size, some having an area 
of several hundred acres. Before they were converted into reservoirs, 
they held storm waters and collected some flood water, so that the 
bottoms were covered with silt. There are no trees to shield them 
from the wind. 
Rigden lake is a natural basin one mile east and two miles 
south of the Agricultural College. It has neither inlet nor outlet. 
Some seepage shows on the inclined sides of the basin during the 
summer season, and the ground is soft in places. The lake collects 
the waste and seepage waters from irrigated land to the west. The 
nearest ditch that is more than a small lateral, is over a mile away. 
The lake is not fully exposed to the wind, being below the surface 
of the plain, and protected by a grove of cottonwoods a few rods to 
the west, and another a short distance to the east. 
Warren lake lies a mile and one half south of Rigden lake, and 
is used as a reservoir. Tt has an embankment on the northeast side. 
Some seepage water enters at the west side, and also waste water 
from irrigation. Observations on evaporation were carried on in 
this lake for several years. The observations on loss by seepage 
were of no result, as the company found it convenient to fill the lake, 
and the filling, together with the seepage inflow, made the observa- 
tions inconclusive. 
