Damage and inconvenience due to a sewage backup can be prevented or significantly reduced with the installation of a backwater valve. If a structure has a plumbing fixture below the public sewer system, a backwater valve can help stop sewage from backing into your business or home when the public system has a blockage. A properly installed backwater valve works on a one-way system; sewage can flow out, but not back in, therefore preventing damage to your property.
Not all homes or commercial buildings need a backflow valve. New structures, new installation or alterations of plumbing fixtures require the installation of a backwater valve if the lowest finished floor elevation is less than one foot above the uphill manhole cover of the public sewer system. Existing homes or commercial buildings located in older parts of Los Gatos may have been constructed or had plumbing repairs completed before the requirement of a backwater valve and may need backflow protection. Los Gatos Town Code section 22.20.055(b) provides the Town of Los Gatos is not liable for damage resulting from sewer overflow where the property owner or other person has failed to install and maintain a backflow valve.
The Town suggests that while you are working on your plumbing system you have your plumber or West Valley Sanitation District investigate your property to see if a backwater valve is necessary to protect your property. Although the cost can vary, the one-time cost may save your personal property and help eliminate potential unnecessary hardships.Backwater Valve Handout