Outdoor Drainage Fixtures

Did you know that outdoor showers and sinks utilize a sewer lateral to transport wastewater to the sewer main? These private laterals are under RVSD’s jurisdiction if they reside outside a building footprint. If you are planning to install an outdoor shower or sink, you will need to apply for a lateral permit with RVSD, and have the work inspected by a District Inspector.

According to California Plumbing Code Section 1101.3 and RVSD Sanitary Code Section 601, storm water drainage is prohibited to enter the sanitary sewer system. To avoid dedicating wastewater collection and treatment capacity to handling of clean water, surface or sub-surface drainage, rainwater, storm water, seepage, cooling water or unpolluted industrial process waters shall not be drained into any sanitary sewer by any device or method whatsoever. This includes leaders from roofs and surface drains for rainwater.

Outdoor drainage fixtures can be a source of inflow & infiltration (I&I). When storm water enters the sewer system through I&I, it can cause sewer spills and backups in your home. Additionally, I&I can overwhelm Central Marin Sanitation Agency’s treatment plant, leading to the discharge of partially untreated wastewater into the bay. The District needs your assistance in ensuring that I&I is reduced by not allowing rainwater to enter the sewer system.

Considering installing an outdoor drainage fixture? Explore the tabs below to see what the District requires.


  1. Swimming Pools
  2. Outdoor Sinks & Showers
  3. Surface Area Drains
  • It shall be unlawful for any person to discharge the contents of a swimming pool into a sanitary sewer except where approved and permitted by the District. No swimming pool shall be physically connected to the sewer system.
  • The draining of water from swimming pools, spas and/or fountains to the sanitary sewer shall only be conducted under an approved permit issued by the District. 
  • RVSD will allow swimming pools, spas, or swimming pool/spa filter backwash to be drained into the sanitary sewer provided that the property owner adheres to the following requirements specified in Appendix B of RVSD’s Standard Specifications & Drawings:Pool Opens in new window
      • Notification: Pool Drain Permit must be obtained and notification must be provided to RVSD a minimum of 48 hours prior to draining swimming pools, spas, or swimming pool/spa filter backwash into the sanitary sewer system.
      • Air Gap: The drained and/or pumped water must pass through an air gap tank prior to discharge into the sewer to prevent overflows. See Standard Drawing SD-41 (pg 443).
      • Side Sewer Cleanout: Discharge must be into a sanitary sewer cleanout. If the property’s sewer lateral does not have an existing cleanout, the installation of a new sewer cleanout may be required.
      • Max Flowrate: The flowrate of the discharge into the sanitary sewer shall not exceed 50 gallons per minute at any time.
      • Weather: Draining must occur during dry weather. The discharge of swimming pools or spas into the sanitary sewer system during rain events will not be allowed.