Buying Land in Madison County, Illinois

Zoning: countywide, split between a Zoning Coordinator and a Planning Coordinator

Madison County Planning & Development, headquartered at 157 N. Main Street, Suite 254 in Edwardsville, manages land use, zoning, building codes, and development review for unincorporated Madison County. Day-to-day zoning administration -- zoning-map amendments, special-use permits, variances -- runs through the department's Zoning Coordinator ((618) 296-4662), while broader growth, comprehensive planning, and subdivision-review functions run through a separate Planning Coordinator ((618) 296-4985). Both operate out of the same Edwardsville office. Madison County has an unusually large number of incorporated municipalities for an Illinois county of its size -- Edwardsville, Alton, Granite City, Collinsville, and many others -- each of which supersedes county zoning entirely inside its own corporate limits, so confirm whether a specific parcel is unincorporated before assuming the county code applies.

Madison County has 24 townships and uses Illinois's standard township form of government rather than the commission form used by 17 of the state's 102 counties overall. Because the county has adopted a countywide zoning code, Illinois's Article 110 township zoning does not independently apply in any Madison County township -- Planning & Development is the operative authority for unincorporated land regardless of which township it sits in.

Flood risk: the American Bottom, and what happened in 1993

A significant share of Madison County's lower-elevation land sits inside the American Bottom, the Mississippi River's floodplain running roughly 90 miles from Alton south to the Kaskaskia River, averaging about 5 miles wide and covering roughly 450 square miles (288,000 acres) across Madison, St. Clair, Monroe, and Randolph Counties. That geography has produced a real, repeated flood history rather than a theoretical one. In 1903, the Madison County levee running from near Venice eastward to Mitchell broke on June 6, flooding the American Bottom industrial cities of the era -- a disaster significant enough that the Illinois Legislature created the East Side Levee and Sanitary District (covering Madison and St. Clair Counties) by enabling act in 1907, permanently organized in 1909.

The more consequential flood for anyone evaluating property today happened in the summer of 1993, when historic Midwest rains pushed the Mississippi and Missouri Rivers to record levels. In Alton specifically, the river crested 21.7 feet above flood stage, and downtown Alton's defenses -- built up by residents and volunteers sandbagging around the clock -- were ultimately beaten not by the river topping the levee outright, but by floodwater burrowing through the ground and through sewage pipes underneath the levee and bursting up through the pavement behind it. FEMA didn't officially declare an end to the 1993 flood incident period in Illinois until October 22, 193 days after it began, and residents up and down the Calhoun, Jersey, and Madison County riverfronts lost homes in the process.

That history is why Madison County's own floodplain administration is a genuinely active part of the county's Planning & Development department rather than a formality: the county's Building & Zoning Division maintains at least two Certified Floodplain Managers (CFMs) on staff, a new structure proposed within a mapped Special Flood Hazard Area must include an Elevation Certificate showing the lowest finished floor at least 2 feet above the Base Flood Elevation (or an approved FEMA Letter of Map Change), and land development within a mapped floodway is prohibited without an IDNR permit and FEMA approval. Failing to enforce these standards would put the county's own NFIP enrollment at risk -- and with it, every property owner's ability to buy federally backed flood insurance. See our dedicated flood-zones page for what this means when evaluating a specific parcel.

Metro East growth: St. Louis's suburban edge, moving inland

Madison County is the northern half of the "Metro East" region of Greater St. Louis, and its 2020 population of 265,859 makes it the eighth-most populous county in Illinois and the most populous county in the state's southern half. Edwardsville, the county seat and home to Southern Illinois University Edwardsville, sits about 18 miles northeast of downtown St. Louis; neighboring Glen Carbon, about 14 miles out, has grown alongside it. A documented population shift over recent decades has moved people away from older, lower-lying, industrial river-bottom cities -- East St. Louis and Alton chief among them -- toward bluff-top suburban communities like Edwardsville, Glen Carbon, Belleville, and O'Fallon that sit above the American Bottom's flood exposure.

For a land buyer, that combination is worth holding in mind together: growth pressure is concentrating on higher ground away from the river, which is both a market signal (rising demand and land values in the Edwardsville/Glen Carbon corridor) and a practical explanation for why so much of the county's older river-bottom acreage has depopulated even as the county overall has grown. A parcel's specific elevation and flood-zone status, not just its general location in the county, should drive both the zoning conversation and the flood-risk conversation.

Septic, GIS, and other departments to know

Private sewage disposal in Madison County runs jointly through Planning & Development (which permits and inspects installations, with a follow-up inspection six months after completion) and the Madison County Health Department (101 E. Edwardsville Road, Wood River; (618) 692-8954), which collects the roughly $370 sewage permit fee; private sewage is only permitted where public sewer is unavailable and cannot be extended to the property line. The Chief County Assessment Office's GIS/Maps and Plats Division (157 N. Main Street, Suite 229, Edwardsville; (618) 692-6270 for the assessment office generally, (618) 692-7040 ext. 1964 for GIS) enforces the Plat Act and maintains the county's roughly 2,300 tax maps covering more than 136,000 parcels, the Recorder of Deeds verifies subdivision and annexation plats before recording, and University of Illinois Extension serves Madison County jointly with Monroe and St. Clair Counties, with a local office at 1 Regency Plaza, Suite 200, Collinsville ((618) 344-4230).