Who stops flushing their toilet in a recession? If you answered "me," then please go flush first before you come back to read this article.

Besides their obvious stability, water companies have an underground catalyst: ancient pipes. The U.S. is chock-full of decrepit water and sewage pipes -- some wooden -- that need to be replaced. Additionally, cash-strapped municipalities are hawking their utilities to capable private water companies like Aqua America (NYSE: WTR). Aqua America in particular has been buying up smaller utilities to boost its growth rate.

Other utilities include York Water (Nasdaq: YORW) and California Water (NYSE: CWT). A more aggressive play could be hard-goods maker Mueller Water Products (NYSE: MWA), while international investors may want to peck at a larger conglomerate such as Veolia (NYSE: VE) or GDF Suez spinoff Suez Environment.

Watch the video for more on the water industry: