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Datacenter Sites in Johnson County, Iowa

Johnson County has 112 scored datacenter candidate sites averaging 57.9/100 DC Readiness, with a catalogued aggregate of 2,506 MW. FEMA rates local natural-hazard risk as "Relatively Moderate". The county has a datacenter tax incentive on record.

At a glance

Johnson County, Iowa has 112 scored datacenter candidate sites averaging 57.9/100 DC Readiness, roughly in line with the Iowa average of 56.3. It ranks 4th of 85 Iowa counties by number of sites and 24th by average score. The top-scoring site is TIFFIN at 68.1/100.

112
Candidate sites
57.9/100
Avg DC Readiness
2,506 MW
Catalogued capacity
theoretical aggregate
Relatively Moderate
Hazard rating
◆ Loading map…
≥ 7560–7540–60≤ 40
Top 25 in Johnson County

Site-selection context for Johnson County

Yessales_tax_exemption
Datacenter tax incentive
11.80¢/kWh
Commercial electricity
7.69¢/kWh
Industrial electricity
18
Fiber providers
Low
Water stress
$10,307
Land price / acre
900
Cooling degree days
6,500
Heating degree days
48°F
Mean annual temp

Incentive detail: Sales tax exemption on DC equipment for $1M+ investments; property tax phase-in for new construction.

How does Johnson County compare with other counties in Iowa?

By number of scored sites, Johnson County ranks 4th of the 85 Iowa counties with a county page, holding 4.4% of the state's 2,572 sites. Its average DC Readiness of 57.9/100 ranks 24th in the state and is roughly in line with the national average of 53.0. Nationally it has the 283rd-largest site inventory of 2,964 counties with five or more sites. 0 sites score 70 or higher and 112 score 55 or higher.

What types of datacenter sites are in Johnson County?

Industrial sites are the most common (88, 79% of the county's inventory), followed by substation-adjacent (14) and greenfield (8). Site type reflects how the parcel was identified — next to a substation, on a former mine or brownfield, on industrial or federal excess land — and is scored on the same 14 factors either way.

What are power cost, hazard, water and fiber conditions in Johnson County?

Industrial electricity averages 7.69¢/kWh and commercial 11.80¢/kWh. FEMA's National Risk Index rates the county "Relatively Moderate" (30). WRI water stress is low. 18 fiber providers report service in the county. The climate runs 900 cooling degree days a year with a mean temperature of 48°F. Land is valued around $10,307 an acre.

By site type

Top datacenter sites in Johnson County

Top datacenter sites in Johnson County
SiteTypeVoltageCapacityQueue waitScore
TIFFINSubstation-Adjacent345 kV600 MW4.3 yrs68.1
HILLSSubstation-Adjacent345 kV600 MW4.3 yrs67.2
EC Near University of Iowa Main Power PlantGreenfield——4.3 yrs65.8
RISER137658Substation-Adjacent161 kV100 MW4.3 yrs63.6
UNKNOWN159106Substation-Adjacent161 kV100 MW4.3 yrs63.6
UNKNOWN137654Substation-Adjacent161 kV100 MW4.3 yrs63.6
EC Near University of Iowa Main Power PlantGreenfield——4.3 yrs62.7
UNKNOWN132168Substation-Adjacent161 kV100 MW4.3 yrs62.7
UNKNOWN132172Substation-Adjacent161 kV100 MW4.3 yrs62.5
UNKNOWN132171Substation-Adjacent161 kV100 MW4.3 yrs62.5
UNKNOWN137657Substation-Adjacent161 kV100 MW4.3 yrs62.4
UNKNOWN132173Substation-Adjacent161 kV100 MW4.3 yrs62.4
UNKNOWN137652Substation-Adjacent161 kV100 MW4.3 yrs62.2
UNKNOWN137713Substation-Adjacent161 kV100 MW4.3 yrs62.1
EC Near University of Iowa Main Power PlantGreenfield——4.3 yrs61.9
EC Near University of Iowa Main Power PlantGreenfield——4.3 yrs61.9
SUTLIFFSubstation-Adjacent115 kV100 MW4.3 yrs61.0
WEST BRANCHSubstation-Adjacent115 kV100 MW4.3 yrs61.0
University of Iowa Main Power PlantBrownfield—6 MW4.3 yrs60.4
Mine SiteFormer Mine——4.3 yrs57.2
EC Near University of Iowa Main Power PlantGreenfield——4.3 yrs57.0
Summit HillsIndustrial——4.3 yrs57.0
Grell PropertyIndustrial——4.3 yrs57.0
Wissink PropertyIndustrial——4.3 yrs56.9
212 East 10th St.Industrial——4.3 yrs56.9

Every scored site in Johnson County

All 112 sites, best first.

Johnson County datacenter FAQ

How many datacenter sites are in Johnson County?

112 scored datacenter candidate sites, averaging 57.9/100 DC Readiness. That is the 4th-most of 85 Iowa counties with five or more sites.

What is the highest-scoring datacenter site in Johnson County?

TIFFIN scores 68.1/100 DC Readiness, the highest of the 112 scored sites in Johnson County (a substation-adjacent site).

Does Johnson County offer datacenter tax incentives?

Sales tax exemption on DC equipment for $1M+ investments; property tax phase-in for new construction.

What is the natural-hazard risk in Johnson County?

FEMA's National Risk Index rates Johnson County as "Relatively Moderate" (score 30).

What are industrial electricity rates in Johnson County?

Average industrial electricity is 7.69¢/kWh and commercial is 11.80¢/kWh in Johnson County.

More in Iowa

About this data

Source: GridCensus composite of HIFLD transmission and substation data, EIA, FEMA National Risk Index, FCC broadband data, PeeringDB and ISO interconnection queues, as published November 12, 2026 — GridCensus refreshes it monthly. See the methodology for how records are matched, cleaned and scored.

Cite as: GridCensus, “Datacenter candidate sites in Johnson County, Iowa”, https://gridcensus.com/datacenter-sites/iowa/johnson-county (data as of November 12, 2026).

Dataset updated . Screening estimates derived from public data sources.

Go deeper than the public screen

Every site and score for Johnson County, Iowa is free to browse. Pro adds Watchtower on 25 sites, alerts when new candidate sites, datacenters or interconnection-queue requests appear in your markets, score and capacity history, and CSV export. Enterprise adds team seats, weekly data files for all 147,272 sites, the REST API and an MCP server for AI tools.

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