Fig. 14.—Sketch Plan Of Lay Out At Obispado Reservoir.
[Larger.]

The general plan of the scheme is shown by Fig. 14 and [Fig. 2, Plate XVIII]. The roof, which has an area of 1 hectare, has been laid out with walks and grass plots, and the surrounding embankments have been converted into driveways. Above the reservoir a small plazuela of 1⁄2 hectare has been laid out with a space above it for a band-stand. The whole of the ground has been encircled with carriage drives, on which it is the intention to plant shade trees. The lay-out of this land also embraced the scheme for protecting the reservoir by draining the surface-water away to the irrigation ditches.

Comparison of South and Obispado Reservoirs.

The two reservoirs are practically of the same capacity, the only difference being the level of the overflows in their relationship to the roof, which gives the Obispado Reservoir a slightly greater capacity. Some comparative figures may be of interest, owing to the differences in type and construction. Table 7 gives the comparative quantities of material in each reservoir proper, that is to say, exclusive of the valve-houses, lay-out of grounds, etc.

TABLE 7.—Comparison of Materials in South and Obispado Reservoirs.

South Reservoir.Obispado Reservoir.
No.Quantities,
in cubic meters:		No.Quantities,
in cubic meters:
Earthwork:
Total excavation...34,000...56,479
Placed in embankment...31,500...7,255
Placed in spoil banks...2,500...49,224
Concrete:
Columns (including foundations)1351,240356543
Primary beams135440374462
Secondary beams6705151,252576
Side-walls...1,255...710
Roof slabSquare
meters:
5,140		520Square
meters:
10,206		1,020
Floor4,0707809,2002,120
Parapet walls...90...165
Total concrete...4,840...5,596
Reinforcing steel bars...Pounds:
387,000		...Pounds:
380,000
Expanded metal in roofs, slabs, etc....Square
meters:
5,691		...Square
meters:
10,490

The total cost of these reservoirs, including valve-houses, by-passes, and the length of supply pipe where the by-pass joins, and including all engineering expenses, etc., but exclusive of the cost of lands, planting, fencing, and special work in connection with the formation of parks, was as follows:

South Reservoir: 394,000 pesos, or 10,368 pesos per million liters.