142 
BATHYMETRICAL SURVEY OF 
bottom, with drains running through it, and overflows when the depth of 
water at the north end attains 10 feet, the south end being about 3 feet 
deeper. The area draining into the reservoirs is about 4 square miles. 
South Settling Reservoir . — The south pond is the larger of the two, 
being nearly half a mile in length, by nearly one-third of a mile in 
breadth, covering an area of about 73 acres, and containing about 43 
million cubic feet of water. The deepest sounding in 26 feet was taken 
near the middle but towards the west side, where there is a considerable 
area, equal to about 21 per cent, of the total area, covered by more than 20 
feet of water. The mean depth is estimated at 13 J feet. The temperature 
of the water was nearly uniform throughout, the reading at the surface 
being 47°T Fahr,, at 10 feet 47°*0, and at 25 feet 46°*8. 
North Settling Reservoir . — The north pond is nearly half a mile in 
length, by a quarter of a mile in maximum breadth, covering an area of 
about 47 acres, and containing about 26 million cubic feet of water. The 
deepest water occupies the north-eastern part of the pond, the maximum 
depth of 22 feet being recorded close to the north-east shore, while an 
isolated sounding in 20 feet was taken close to the western shore, near the 
channel leading to the south pond. The mean depth is estimated at 12^ 
feet. The surface temperature was 46°*8 Fahr, 
Cromhie Den Reservoir (see Plate L.) lies about 2 miles to the north- 
west of Monikie reservoirs, and is most irregular in outline. The wide 
central portion is occupied by a large island, around which the water of the 
reservoir forms a narrow channel, sending out a narrow shallow arm to the 
west, and a wider deep arm to the south-east. The length from north-west 
to south-east is nearly a mile, while the maximum breadth is only about 
one-ninth of a mile, the superficial area being about 41 acres, and the 
drainage area about 24 square miles. The maximum depth of 53 feet was 
observed oft* the sluice at the south-east extremity of the reservoir, whence 
the water shoals gradually towards the inflow at the opposite extremity. The 
mean depth is estimated at 18 feet, and the volume of water at 31 million 
cubic feet. The elevation could not be determined from bench-mark, but is 
apparently about 500 feet above the sea. The reading on the sluice on 
October 14, 1904, was 18' 9. The water was practically uniform in 
temperature throughout, the reading at the surface being 47°*5 Fahr., at 5 
feet 47°’2, and at 50 feet 46°-9. 
