Off-Grid Living in Johnson County, Iowa

I've researched Johnson County's off-grid living rules by combing through the county's Unified Development Ordinance, building and public health department documentation, and cross-referencing Iowa state law. What emerged is a patchwork: crystal-clear rules for septic and wells, significant gaps for newer off-grid technologies, and a critical jurisdictional split between unincorporated county land and five incorporated towns. Before you commit to a property here, you need to know which authority governs your parcel and which questions only they can answer.

Know Your Jurisdiction First

This is the single most important step. Johnson County is not one monolithic jurisdiction. Unincorporated land falls under Johnson County zoning (administered through the Unified Development Ordinance adopted in 2019). But if your property lies within the municipal boundaries of Iowa City, Coralville, Lone Tree, Oxford, or Swisher, that town's zoning and building rules apply instead—and they differ from the county baseline.

I recommend calling the Johnson County Planning & Development office (part of the Department of Planning, Development and Sustainability) and asking them to confirm: (1) whether your parcel is in the unincorporated county or inside a town, and (2) if inside a town, to provide contact info for that town's planning department. This one phone call will save you months of confusion later. Once you know your jurisdiction, you apply the rules of that authority, not the other.

Zoning: Restricted in the County, Variable in Towns

Johnson County's Unified Development Ordinance (UDO) establishes zoning for unincorporated areas. The ordinance is enforced by the county Planning & Development office. I reviewed the 2020 edition and found that the county does use standard zoning districts (residential, agricultural, commercial, industrial). Lot sizes, building setbacks, and permitted uses vary by district.

Off-grid suitability is heavily zone-dependent. Agricultural zones typically allow greater flexibility than residential zones, and larger minimum lot sizes often support septic and well systems better than dense subdivisions. However, I did not find explicit blanket approval or prohibition of off-grid living within any single zone in the UDO itself. What I did find is that building permits and wastewater permits (the real gatekeepers) are issued by separate departments—Planning & Development for general construction, and the Public Health Department for septic and wells.

What to do: Contact Johnson County Planning & Development and ask (1) your zone designation, (2) the minimum lot size for your zone, and (3) whether off-grid living (well and septic) is explicitly permitted or restricted in your zone. If you're in a town, ask that town's planning office the same questions—rules there may be stricter or more permissive.

Dwelling Units and Tiny Homes: A Critical Gap

Johnson County adopted the 2018 International Residential Code (2018 IRC) as its building standard. The 2018 IRC includes Appendix Q, which provides standards for tiny homes (dwelling units typically under 500 square feet). However, I found no evidence that Johnson County adopted Appendix Q itself.

This is significant. Adoption of the IRC does not automatically include its appendices. Without Appendix Q adoption, tiny homes may fall into a gray area: are they treated as RVs (not permitted for year-round occupancy on raw land), as accessory dwelling units (subject to separate rules), or as non-compliant dwellings (prohibited)? I cannot definitively answer this from the public record.

Similarly, Iowa state law permits tiny homes and yurts, but only if the local jurisdiction approves them. Johnson County's UDO does not explicitly mention tiny homes, which suggests they may not be permitted in county zoning—but this is an inference, not a confirmed rule.

What to do: If tiny homes, yurts, or other alternative dwelling types interest you, call the Johnson County Planning & Development office directly and ask whether they are permitted in your zone. Get this in writing if possible. If your land is in a town, contact that town's planning department instead. This is not a question you can resolve by reading the UDO; you need verbal confirmation from the office that reviews permits.

Building Permits and Erosion Control: Layered Compliance

Any new single-family dwelling in Johnson County requires a building permit from the Planning & Development office. Additionally, any structure that disturbs more than one quarter acre of ground, or any dwelling, must include a Soil Erosion and Sediment Control (SESC) plan submitted with the permit application.

This is a real requirement but not an off-grid barrier. The SESC plan shows how you will prevent soil erosion and sediment runoff during construction—for example, by using silt fences, erosion control mats, or sediment basins. In practice, a contractor or engineer familiar with Johnson County can draft this quickly and inexpensively. It adds a step but is routine for new construction.

Additionally, all new homes must meet visitability standards in the Johnson County Building Code. Visitability means the home must have zero-step entry (or a ramp), at least one accessible bathroom, and hallways wide enough to accommodate mobility devices. This is a universal design requirement, not specific to off-grid living, but it is mandatory. Again, not a barrier—most modern single-family homes already meet this—but something to budget for and discuss with your designer or contractor.

What to do: When you apply for your building permit through Johnson County Planning & Development, ask for a SESC plan template and the current visitability standards checklist. If you hire a local contractor, they will be familiar with these. Budget for the SESC plan and ensure your home design meets visitability standards from the outset.

Septic Systems and Wastewater Permits: The County's Clear Authority

This is the area where Johnson County has the most transparent and direct oversight. All new homes require a wastewater permit from the Johnson County Public Health Department (855 S Dubuque Street, Iowa City, IA 52240; phone 319-356-6040). The Public Health Department designs the septic system, approves the site, and issues the permit.

Iowa state law mandates that all wastewater discharge into a septic tank as the primary treatment unit. This means if you are not connected to a municipal sewer system, you must have a septic system. Composting toilets or waterless systems cannot be your sole wastewater disposal method under Iowa law—they may be ancillary, but septic is required.

The process is straightforward: (1) you contact Public Health with your property location, (2) they conduct a site evaluation (soil percolation test, depth-to-water-table assessment, etc.), (3) they design the system, (4) you obtain a permit, (5) a licensed contractor installs it, (6) Public Health approves the installation. This typically takes a few weeks to a couple of months.

I did not find evidence that Johnson County allows alternative systems such as aerobic treatment units or sand mounds as of my research date, but systems and rules do evolve. Ask the Public Health Department whether alternatives to conventional gravity-fed septic are approved for your site—some newer systems can work on sites with poor soil conditions or high water tables.

What to do: Contact the Public Health Department (319-356-6040) early in your property search, ideally before you buy. Tell them your approximate property location and ask whether a septic system is feasible there. They can often give you a quick assessment over the phone. Once you own the land, formally request a site evaluation. Budget 4–8 weeks for the full process if your site is straightforward; longer if it requires engineered solutions.

Private Wells: Permitted with Conditions

Johnson County also permits private wells through the Public Health Department (same office and phone number as septic). Wells require a permit and must meet Iowa's drinking water standards.

One important rule I found: if a well serves more than two lots or properties, it requires a stand-alone preliminary plat. This is a subdivision-level regulatory requirement, not a prohibition. In practical terms, if you want a shared well with a neighbor, it may be allowed informally; if you want to serve three or more properties from one well, you will need to formally subdivide and plat the arrangement with the county. This rule is designed to prevent sprawling informal shared-well schemes that the county cannot monitor or enforce.

Iowa state law requires all private wells to undergo water quality testing: annual coliform bacteria testing and nitrate testing. The Public Health Department or your local water utility can provide approved labs. These tests cost $50–150 per year typically and are your responsibility to arrange and pay for.

What to do: When you contact Public Health about septic, also ask about their private well permit process and whether your intended well location will work. Ask about water quality testing requirements and which labs they approve. Budget for annual testing ($50–200/year) and plan to keep records.

Greywater Reuse: Unregulated at the County Level

Johnson County does not define greywater reuse rules in its UDO or building code. Iowa state law is also silent on greywater reuse—by default, greywater (water from sinks, showers, washing machines) must flow to an approved drainage system, which typically means it goes into your septic tank alongside blackwater.

This is not a prohibition, but it is an absence of explicit permission. If you want to capture greywater and reuse it (for irrigation, toilet flushing, etc.), you would need to seek approval from the Johnson County Public Health Department and possibly the Iowa DNR. However, I found no documented pathway for this approval in Johnson County's public health rules.

What to do: If greywater reuse is important to your off-grid plan, contact the Public Health Department directly and ask whether it is permissible under the county wastewater code. Ask for written guidance if possible. It is possible that a well-designed system could be approved on a case-by-case basis, but I cannot confirm this from the public record. Do not assume it is allowed; get written permission before you design your system.

Rainwater Harvesting: State Law Permits It; Confirm Locally

Iowa state law does permit rainwater harvesting for non-potable use (irrigation, toilet flushing, dust control, etc.), and the state actively encourages it through the Iowa Rain Campaign. There is no state statute restricting rainwater collection from residential roofs.

However, Johnson County does not set its own rainwater harvesting rules at the county level. Some Iowa municipalities do restrict rainwater systems (typically to control stormwater runoff or septic load), so this is worth confirming locally.

What to do: Before you design a rainwater harvesting system, contact your town or the Johnson County Planning & Development office and ask whether rainwater harvesting is permitted in your zone and whether there are any design requirements (tank size limits, overflow standards, etc.). If your system is large (multiple thousands of gallons), also ask whether it triggers a plumbing code review. In most cases, small residential systems (a few hundred gallons) are uncontroversial, but it is worth confirming.

Utility Disconnection: Assumption Rather Than Explicit Rule

Johnson County does not explicitly address disconnection from public utilities (electricity, gas) in its zoning or building code. Iowa state law does not compel rural utility connection where an approved well and septic system are in place. So in theory, if you have a valid private well, septic system, and a non-utility power source (solar, wind, generator, etc.), you should be able to operate off-grid.

However, "in theory" is not the same as "confirmed." Some towns in Iowa require utility hookups for occupancy permits, and the assumption may exist at the local level that utility connection is required. This is unconfirmed for Johnson County and its towns.

What to do: Contact the Johnson County Public Health Department or your town's planning office and ask explicitly: "If I have an approved private well and septic system, am I required to connect to the public electrical grid, gas line, or other utilities in order to receive an occupancy permit?" Get the answer in writing. This is a yes-or-no question, and you need clarity before you build.

The Practical Sequence for Off-Grid Property in Johnson County

Here is the order I recommend:

1. Identify your jurisdiction. Is your land in unincorporated Johnson County or within Iowa City, Coralville, Lone Tree, Oxford, or Swisher? Call the county Planning & Development office to confirm.

2. Contact the appropriate planning office. Ask for zoning designation, minimum lot size, and whether off-grid living (well and septic) is permitted in your zone. If tiny homes or other alternative dwellings interest you, ask specifically.

3. Call the Public Health Department (319-356-6040). Ask about septic feasibility, well permit process, water quality testing, and (if relevant) greywater or alternative wastewater systems.

4. Ask about utilities. Confirm with your town or county that utility disconnection is legal if you have an approved well and septic.

5. Confirm rainwater and greywater. Ask your planning office whether rainwater harvesting and any greywater reuse you are considering are permitted.

6. Get it in writing. Major confirmations—especially regarding tiny homes, alternative dwellings, greywater, and utilities—should be documented in writing from the permitting office.

7. Once you own the land, formally request septic and well site evaluations from Public Health.

Summary of Local Contacts

• Johnson County Planning & Development: Part of the Department of Planning, Development and Sustainability. Website: johnsoncountyiowa.gov/pds. Phone: Not listed individually on the website, but you can reach the main department line and ask for Planning & Development.
• Johnson County Public Health Department: 855 S Dubuque Street, Iowa City, IA 52240. Phone: 319-356-6040. (Wastewater and well permits.)
• Towns: If your land is in Iowa City, Coralville, Lone Tree, Oxford, or Swisher, contact that town's planning/zoning office directly.

Johnson County's off-grid framework is workable but requires homework on your part. The county has clear rules for septic and wells but leaves several areas—tiny homes, greywater, rainwater, utility disconnection—to local interpretation or explicit confirmation. None of these areas are necessarily deal-breakers, but each one needs clarification before you commit to a property. Start with a phone call to Planning & Development and Public Health. That one conversation will anchor the rest of your research.