Building permits, zoning and septic rules across Missouri counties

Missouri has 54 counties without countywide zoning, including Texas County, Bollinger County, Dallas County³. County zoning is present in 29 counties, and we could not confirm the zoning answer for 32 counties⁸. Missouri county zoning authority applies to unincorporated territory; an address inside city limits needs the city's answer⁴.

The no-zoning list identifies counties without countywide zoning, while the no-building-permit and no-zoning list narrows the overlap to 50 counties^3,9. A no-zoning answer does not remove Missouri septic approval or floodplain development requirements, so ask the septic authority and community floodplain administrator about the parcel before choosing a house site^5,12.

Missouri's septic authority pattern is 45 counties with state-agency permitting, 6 served by a health district and 64 with county permitting; Missouri DHSS is the common state agency⁸. Start with the DHSS Onsite Wastewater Treatment Program's permitting-authority lookup to identify the agency for the work location⁵.

Missouri requires a construction permit before installing or repairing most onsite wastewater systems; some single-family lots may qualify for an exemption, and work must wait for a permit or confirmed exemption⁵. Residential lots smaller than 3 acres require a septic permit, and the acreage exemption does not apply in some counties⁵. DHSS application fees for construction, modifications and repairs are temporarily suspended effective August 28, 2026; local processes may vary, so ask the permitting authority about current charges⁵. DNR handles non-single-family lagoons, surface-water discharges and certain larger systems⁵.

Missouri's highest Bolthole Index scores start with Texas County, Bollinger County, Dallas County: Texas County scores 81, while Bollinger and Dallas counties score 80 on the off-grid and homestead land index⁸. These counties have no residential building-permit requirement and no countywide zoning; septic authority is county-level in Texas and Dallas counties and state-level in Bollinger County⁸.

Sullivan County also scores 80 and has no residential building-permit requirement, but its zoning answer remains unconfirmed; its septic authority is state-level⁸. Missouri's median county farmland value is $4,465 per acre, a farmland benchmark rather than an individual parcel asking price⁸. The median county effective property-tax rate is 0.7%, and the median county property-tax bill is $1,101 annually; use these medians as context when comparing counties⁸.

Missouri follows riparian reasonable-use water principles, with domestic and farm groundwater use described as unregulated under reasonable use¹⁰. Water-use status does not remove well-construction requirements: Missouri requires appropriate installation permits for regulated contractors, while landowners may install their own well or pump without a permit under the applicable law and rules¹¹. Ask Missouri Geological Survey about construction standards and any needed variance before drilling¹¹.

A public water system needs DNR written approval before constructing or altering a public well, subject to the stated statutory exemptions¹³. For road access, constructing or modifying a driveway within MoDOT right-of-way requires a MoDOT permit; the rule does not establish requirements for driveways outside that right-of-way¹⁴. Contact the area Traffic Specialist at least 48 hours before permitted right-of-way work begins¹⁵.