Why this score?
Four weighted factors drive the Marion County risk score. Methodology is fully documented — each input is public data or a reasoned proxy.
Served by Ameren Missouri. Above-average transmission capacity via Ameren Missouri grid.
Water source: Mississippi River (Hannibal). Major river access — ample for industrial cooling with standard permitting.
Moderate availability of large parcels.
No active projects nearby. Lower immediate pressure, but conditions can change quickly with a single developer announcement.
Water infrastructure
Marion County has access to the Mississippi River — one of Missouri's most abundant surface water sources.
The Mississippi River provides ample water for industrial cooling, and proximity to it is a factor developers consider when siting hyperscale data centers. However, large withdrawals require Missouri DNR permits. Flood risk in the Mississippi River corridor also creates siting constraints for ground-level facilities. A single hyperscale data center can require 1–5 million gallons per day for evaporative cooling.
Electric infrastructure
Marion County is served by Ameren Missouri, the state's largest electric utility, covering eastern and central Missouri with approximately 1.2 million customers.
The Missouri Public Service Commission approved a new large-load rate structure for Ameren Missouri in December 2025, specifically designed for data centers and other large industrial customers. The rate structure ensures these customers pay their full share of infrastructure and generation costs while protecting existing residential ratepayers. Ameren Missouri provides power for the Google and AWS data center campuses under development in Montgomery County.
Under Missouri's SB 4, data centers above 75 MW must pay premium utility rates. However, environmental groups including the Sierra Club have raised concerns that increased data center demand could pressure Ameren to extend the life of its Labadie coal-burning power plant — one of the dirtiest in the country — and build additional natural gas generation on top of the 6.1 gigawatts already in its future plans. Sulfur dioxide emissions at Labadie increased 17% last year.
State legislative context
Missouri's 2026 legislative session directly affects Marion County, regardless of whether a project is currently proposed here.
HJR 173 & 174 proposes eliminating Missouri's income tax and replacing it with expanded sales taxes on services — while data centers continue to receive a sales tax exemption on construction materials, equipment, and utilities for up to 15 years. According to the Missouri Budget Project, 80% of Missourians would face a net tax increase.
At the local level, developers negotiate Chapter 100 industrial revenue bonds that exempt them from real and personal property taxes. Under SB 4, data centers above 75 MW must pay premium utility rates. Many rural Missouri counties have no planning and zoning laws, meaning a data center can be proposed with no public hearing, no zoning review, and no county oversight.