La respuesta puede ser una de dos; o 'water miser' como estrategia (ver el último enlace), o Water Miser como uno en una línea de productos de la empresa Water Miser; si esta traducción se refiere a esa línea, yo no traduciría el nombre, aunque explicaría que es producto 'avaro' de agua,' o sea, que se usa para no desperdiciar sino para conservar el agua.

Watermiser Clean Green products use water saving technology. Flow Control Valves and Miser Blue Toilet Leak Detector.
www.watermiser.com/ - 29k -

Water Miser Battery Caps
Water Misers are molded plastic "flip-top" vent caps designed to reduce and ease maintenance on flooded Lead-Acid batteries.
store.solar-electric.com/batwatmiscap.html

The extension project includes three irrigation strategies: traditional, fully-watered irrigation management, which keeps soil water high enough to prevent moisture stress from limiting yields all season; water miser best management, which focuses on saving water during less sensitive vegetative growth stage and fully watering during reproductive growth stages; and deficit irrigation management, which relies on correctly timing application of a limited amount of water during the growing season and over several years.
http://ianrnews.unl.edu/static/0503141.shtml