Low-flow shower head. Older shower heads deliver as much as 5 to 10 gallons per minute (GPM). Newer shower heads must be water efficient, delivering 2.5 GPM or less at a standard water pressure. Water-efficient, or low-flow, shower heads are designed to provide an acceptable shower at a greater reduced flow rate. Most are equipped with a button to switch the water off at the shower head, to save water while shaving or lathering. Water-efficient shower heads should not be confused with the flow restrictors used in the 1970s and early 1980s, which simply reduced the flow rate far below design level, often resulting in an unacceptable shower.
High quality low-flow shower heads range from $10 - $50 depending on features such as flow adjusting dials and designer styling. Hand-held models are more expensive than fixed models. To determine if you could benefit from a low flow shower head:
Set a 2qt. saucepan on the floor of the shower and position it in the middle of the shower stream. With shower on full, count how many seconds it takes to fill the pan. If it takes fewer than 12 seconds, you should consider a low-flow shower head. If you have a low-flow shower head installed, it should read 2.5 gpm or less.