Float Valve Pond

float valve
A ballcock (also balltap or float valve) is a mechanism, or machine for filling water tanks, such as those found in flush toilets, while avoiding overflow. The modern ballcock was invented by Joseph Bramah and Thomas Twyford.
A valve which is mechanically actuated by a float. Utilized on many cooling towers to control make-up water supply.
A mechanism that regulates fluid level by using a float to control the filling of water in the water tank; used in swamp coolers to regulate water levels.

pond
(of flowing water or other liquids) Form such a lake
A pond is a body of standing water, either natural or man-made, that is usually smaller than a lake.
Hold back or dam up (flowing water or another liquid) to form a small lake
a small lake; "the pond was too small for sailing"
Pond was a grunge band from Portland, Oregon. They formed in 1991 and broke up in 1998. They were signed to Sub Pop (first two albums) and the Work Records sub-label of Sony Records (last album).