Accessory Dwelling Units

Accessory Dwelling Unit TypesAccessory Dwelling Units (ADUs) are attached or detached living spaces which are separate from a primary residence. Also sometimes called Accessory Living Quarters (ALQs) or Accessory Living Units (ALUs), they can include structures such as guest houses, tiny homes, mother-in-law suites, backyard studios, converted garages, pool houses, or any other similar space. Construction of ADUs is governed by local building and development codes, and petitioners should review their plans with their city or county as appropriate.

Connecting Water to an ADU

Potable water service requests for ADUs must be reviewed by WaterOne Staff. WaterOne will require the following information to begin our review of the proposed structure and water service:

  • Proposed water demand for the ADU in either gallons per minute (GPM) or water supply fixture units (WSFU).
  • Plans for the proposed structures must be submitted to WaterOne for review.
  • If the local municipality assigns a new address for the ADU, it must also be provided to WaterOne Staff.

Please submit this information via email along with a Residential Permit Application.

If the additional water demand for the ADU exceeds the rated capacity for the property's current or proposed water meter, then either the meter must be upsized or an additional service connection must be established for the ADU. A separate meter for the ADU can be requested, but WaterOne Staff will ultimately determine how the property will be served.

ADUs that can be served from the primary residence's service line should tap into the private service line located on private property. No tap or modifications can be made between the meter pit and the water main or within the meter pit or within 1-foot of the meter pit on the customers side of the meter pit to accommodate a new private service line. Only new service connections that are paid for and permitted can be tapped on the water main. See WaterOne's service connection charges.

If the property is currently served by a meter that is not located in a meter pit or according to current standards, then WaterOne will require that a meter pit and its accessories be installed outside the home per WaterOne's standards. The installation will be the responsibility of the property owner and the materials for the meter pit and its accessories must be purchased from WaterOne.


If you have any questions, please contact WaterOne Staff via email or 913-895-1815. Please note that non-conforming water connections are against WaterOne's terms of service and can result in action up to and including disconnection of water service to a property.