These stand-pipes are of 6-in. iron pipe standing in a special casting
in the pipe line and enclosed in a concrete base. They are, of course,
open at the top, and vary in height from 15 to 60 ft., depending on the
elevation of the hydraulic grade. They have given some checks on the
position of this grade during the velocity measurements hereinafter
described. Their locations are shown on the profile, Plate V.

_Nogal Reservoir_.--Nogal Reservoir is the storage unit of the system,
and is on the north edge of a table-land, 1,700 ft. above the railway, on
the Carrizozo plain, 15 miles away. It is 11-1/2 miles from the head of
the pipe on Bonito Creek.

This reservoir is a natural basin or bowl, 1/2 mile in diameter across
the top, 1/4 mile on the bottom, and 36 ft. deep. A level line, 1,500 ft.
long, drawn from its bottom, comes out to grade on the north declivity
of the table-land. On this level line an open cut was made and the
outlet pipe laid. The cut was then closed by a dam.

The supply pipe from Bonito Creek delivers water into the basin over the
top of its southern rim, the water, as it leaves the pipe, flowing over
a standard weir, without end contractions, into a stone gutter. A
by-pass pipe, with suitable valves, passes around the western side of
the basin and connects to the outlet pipe.

This comparatively small amount of work equipped a very good natural
reservoir with a capacity of 422,000,000 gal., which can be increased to
1,000,000,000 gal. by embankments across low places in the rim.

_Service Reservoirs_.--At Coyote, an artificial service reservoir, 100