+===========================================================+==========+ | 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.