Buying Land in De Witt County, Illinois

Zoning: one countywide code, run from Clinton on a limited schedule

The De Witt County Department of Planning and Zoning, at 201 W. Washington Street in Clinton, administers the county's zoning ordinance under 55 ILCS 5 Division 5-12 -- reaching unincorporated territory countywide. The ordinance follows the standard Illinois structure: a list of permitted uses by zoning district, specific standards for lot size, building height, and required yards/setbacks, and defined roles for a Zoning Administrator, a Regional Planning Commission, and a Zoning Board of Appeals in administering rezoning requests and appeals. The department also handles rezoning applications directly.

One practical detail worth knowing before you plan a visit: the office keeps limited walk-in hours -- Tuesday and Thursday, 8:30 a.m. to 4:30 p.m. -- with Monday, Wednesday, and Friday available by appointment only. De Witt County uses Illinois's standard township form of government rather than the commission form used by 17 of the state's 102 counties, so under the statewide framework, this confirmed countywide zoning ordinance is the operative authority and independent township zoning under 60 ILCS 1 Article 110 does not apply here.

Septic: a specific, long-standing local policy tying it to your building permit

Septic (private sewage disposal) permitting in De Witt County runs through the DeWitt-Piatt Bi-County Health Department, which serves both De Witt and neighboring Piatt County. The county's own stated policy, in effect since 1978, conditions the issuance of any building permit on the health department's prior approval of plans and provisions for proper water and wastewater handling -- meaning the sequence matters: get your site evaluation and septic plan approved by the health department first, since the county treats that as a precondition for the building permit itself, not a parallel or later step.

This runs on top of the statewide IDPH Title 77 Part 905 private sewage disposal code that applies across Illinois -- see our national guides to perc tests and septic systems for the general process, and confirm current fees and scheduling directly with the bi-county health department.

Clinton Lake: recreation on a privately-owned cooling reservoir

Clinton Lake is a roughly 4,900-acre reservoir with about 130 miles of shoreline, built in the 1970s and opened in 1978 to serve as the cooling-water source for the Clinton Power Station. Unlike Clinton County's Carlyle Lake, which the U.S. Army Corps of Engineers built and owns as a federal public-works project, Clinton Lake is owned by the power plant's operator -- Constellation Energy, which markets the site as the Clinton Clean Energy Center. The public-facing recreation side of the lake operates through the Clinton Lake State Recreation Area, a roughly 9,300-acre IDNR-managed park built around the reservoir, offering camping (over 300 campsites), six boat launches, roughly 25 miles of shoreline trails, and fishing that draws largemouth bass, crappie, catfish, walleye, and hybrid striped bass -- the operator invests annually in fish stocking and works with IDNR on rearing fish for release into the lake.

The practical takeaway for a land buyer near the lake: because the reservoir itself is privately owned rather than a Corps of Engineers or state-owned water body, don't assume the same easement, permit, or shoreline-access framework documented for Carlyle Lake in Clinton County applies here. We were not able to independently confirm the specific mechanics of any private-parcel/shoreline permitting arrangement around Clinton Lake in this research pass -- if you're evaluating a specific near-lake parcel, ask the De Witt County Planning and Zoning Department directly about that parcel's zoning and, separately, ask about the lake owner's own rules for any shoreline access, since public recreation access through the state park does not necessarily extend to private-parcel water rights.

Clinton Power Station just secured a 20-year future

The Clinton Power Station -- a single boiling water reactor with a net capacity reported in the range of roughly 1,060 to 1,090 megawatts depending on the source, located in rural Harp Township -- has been a fixture of the De Witt County economy since it began commercial operation in 1987, and its long-term future has flipped from uncertain to secure in the past few years. In December 2025, the Nuclear Regulatory Commission granted a 20-year license renewal, extending the plant's operating authorization through 2047 under its current owner, Constellation Energy (which spun off from Exelon in 2022). Separately, Constellation announced a 20-year power purchase agreement with Meta (Facebook's parent company) covering electricity generated at the plant, and has committed more than $370 million toward relicensing-related upgrades.

For a land buyer, this matters less as a zoning or permitting fact than as economic context: a major local employer and taxpayer that faced a real possibility of closure in the mid-2010s (before Illinois's 2016 Future Energy Jobs Bill kept it running) now has a locked-in 20-year horizon backed by a long-term corporate power buyer. That's relevant to anyone weighing the durability of the local tax base, job market, or Clinton Lake's continued operation and public recreation access over a multi-decade holding period.

Assessor, recorder, and agricultural extension

The De Witt County Supervisor of Assessments and County Clerk & Recorder handle property valuation records and recorded deeds/easements respectively; we were not able to confirm current direct phone numbers or specific GIS portal details for these offices in this research pass, so start with the county's general website and confirm current contact information directly. University of Illinois Extension serves De Witt County's substantial grain and livestock agricultural sector through a multi-county unit; confirm which specific unit and office currently covers De Witt County directly with Extension, since this research pass did not independently verify that grouping.