Comparison of South and Obispado Reservoirs.
Reading edition
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: 5,140520Square meters: 10,2061,020
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.
Obispado Reservoir: 375,000 pesos, or 9,375 pesos[7] per million liters.
These rates may be regarded as reasonable when taking into consideration the special difficulties of construction in Mexico, and the high cost of all imported material, on which heavy duties are levied.
The value of the materials alone in these reservoirs amounted to more than 70% of their total cost.