Drainage Administration is one of the regulatory activities that the Planning and Development Department provides for the benefit
of the residents of unincorporated Maricopa County. This activity ensures compliance with the drainage regulations for Maricopa County.
The purpose of these regulations is the reduction of existing and potential flooding caused by local stormwater.
The Drainage Regulations apply to all development of land conditions that may affect drainage systems and patterns. The regulation
defines a drainage system as any system or feature over which storm waters flow and development as any man made change to the property.
This regulation also has the definition of drainage as runoff which flows over land as a result of precipitation. This definition
includes sheet flow and flows which may be concentrated, with or without a defined channel.
With regard to obtaining a Drainage Clearance, applicants shall reference the 2010 (draft) Drainage Policies and Standards Manual and the 2009
Methodology Manuals. It can be downloaded for free from the
Flood Control District.
Note: Projects that fall within a designated floodplain may require additional review and approval by the
Flood Control District of Maricopa County.