LOS OSOS GROUNDWATER BASIN
Plumbing Retrofit-to-Build

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The Retrofit-to-Build program (Title 19) requires all new development that uses water from the Los Osos Groundwater Basin to retrofit older plumbing fixtures in existing homes and businesses to save twice the amount of water the new development will use.

Effective March 10th, 2014, toilet and showerhead retrofit credits can no longer come from the Prohibition Zone.

A retrofit credit table has been developed to calculate the savings of each retrofitted house or business. Please utilize this table to calculate the water saving from each retrofitted fixture. Qualifying fixtures include: Toilets, showerheads, and clothes washers.  Water savings will be dependent on gallons saved per day based on the existing and retrofitted fixtures.  Property owners must obtain at least 300 water credits to obtain a Water Conservation Certificate and build a single family home.

Retrofit-to-Build Amounts:

  • Single Family Dwelling - 300 gallons per day water savings to offset new water use

  • Multi-Family Dwelling - 225 gallons per day water savings to offset new water use

  • Accessory Dwelling Unit (ADU) - 150 gallons per day water savings to offset new water use

Retrofit-to-Build Options:

Effective March 10, 2014, retrofit credits, with the exception of clothes washer retrofits, can no longer come from the Prohibition Zone.

Typically, retrofitting 5-6 old clothes washing machines with new, efficient washing machines will save 300 gallons per day. The new washers need to have an Energy Star Integrated Water Factor of 3.2 or less. See a map of the Prohibition Zone on the Los Osos Groundwater Basin main page.

© 2018 by County of San Luis Obispo Countywide Water Conservation Program.