The intake pipe is of cast iron. 40.6 cm. (16 in.) in internal diameter, fitted outside with a movable copper screen which is further protected by a wrought-iron hinged screen to prevent damage from stones, floating timber, etc., during times of flood. Inside the gate-house the outlet pipe is provided with a 40.6-cm. (16-in.) sluice-valve, operated from the floor level by a vertical head-stock with worm-gearing. The gate-house has a scour-out pipe (also operated by a head-stock) and duplicate copper screens fitted to iron frames. From this house the water is conveyed to the upper portion of the conduit, which is a 45.7-cm. (18-in.) cast-iron pipe.
Of the total area of land, 885 hectares (2,187 acres), owned by the company, 392 hectares (970 acres) have been fenced in, to prevent any contamination of the springs. This fence is formed of five lines of barbed wire protected with stout hog netting at the bottom, in order to prevent more particularly the entrance of goats, many thousands of which pasture in the adjoining mountains.
On the high ground immediately below the intake, a 3-roomed stone house has been constructed for the inspector in charge of the intake works, who also keeps in daily touch with the general office and records the condition of the stream, particulars of rainfall, etc.
Aqueduct.—The total length of the aqueduct, from the intake dam to the South Reservoir, is 18,700 m., made up as shown in Table 4.
TABLE 4.—Estanzuela Aqueduct.
| Description. | Length,in meters | ||
| Cast-iron pipes, 45.7 cm. (18 in.) in diameter, along the stream bed of the Estanzuela River | 110 | ||
| Concrete tubes, 55.9 cm. (22 in.) in diameter, to Mederos (including 281 m. of tunnel) | 4,473.81 | ||
| Cast-iron siphons, 45.7 cm. (18 in.) in diameter: | Calabozos | 239 m | |
| South Virgen | 124 " | ||
| North Virgen | 177 " | ||
| Mederos | 426 " | ||
| —— | 966 | ||
| Concrete tubes, 63.5 cm. (25 in.) in diameter, Mederos to South Reservoir. | 12,039.19 | ||
| Cast-iron siphons, 50.8 cm. (20 in.) in diameter: | |||
| Necaxa | 315 m. | ||
| San Augustin | 796 " | ||
| —— | 1,111 | ||
| ——— | |||
| Total | 18,700 | ||
The gradient of the concrete pipes is 0.43% from Estanzuela to Mederos, and 0.53% from Mederos to the South Reservoir. The calculated discharging capacity of the conduit when running full is 364
liters (13 cu. ft.) per sec. for the upper, and 465 liters (16.4 cu. ft.) per sec. for the lower section. For these pipes, the coefficient, n, in Kutter's formula, was taken at 0.013. At present the line has been limited by overflows to discharge three-quarters full.
The increase in the size of the pipes from Mederos is for the purpose of receiving the waters of the Mederos River and other springs in the San Pablo and Aqua Verde catchment areas, as shown on [Plate II].
The invert of the concrete conduit where it leaves the Estanzuela River is 684.25 m. above datum, and at the valve-house of the South Reservoir it is 589.00 m.