The numbers a permit hearing won't show you.
Water draw. Heat output. Carbon flux. Grid load. Wetland storage. Below is what we know about each — and how to verify it on the ground in your own county.
A hyperscale data center is, in plumbing terms, a city.
It draws and evaporates more water than the residential population of the county hosting it — and most of that draw is invisible in the permit application.
The dominant cooling method in newer hyperscale builds is evaporative cooling — the same physics as a swamp cooler at residential scale, but at industrial draw rates. Water is evaporated into the building's airflow to absorb heat from the servers. That water does not return to the watershed. It rises as vapor and falls somewhere else, often outside the basin entirely.
For a 100 MW hyperscale facility, public-record disclosures from existing campuses put steady-state daily water consumption at roughly 1 to 5 million gallons. For comparison, that is the daily draw of a town of ten thousand to fifty thousand people. Permits frequently rely on the operator's own forecasted "design point" rather than measured pull-through after commissioning.1, 2
The grid is being asked to triple, quietly.
U.S. data center electricity demand is on track to roughly triple between 2023 and 2030 — and the cost of new transmission is already showing up on residential bills.
In 2023, data centers consumed about 4% of U.S. electricity. Department of Energy and Lawrence Berkeley modeling has the same number reaching 9–12% by 2030 under current build pipelines. The capacity to deliver that load does not exist yet.3, 4
The capacity to power that growth is not free, and the bill is not landing where the demand is. In multiple states, residential ratepayers are now subsidizing the transmission upgrades that exist to serve hyperscale loads. Ask your utility commission how they're allocating it.
A swamp is doing more, per acre, than you've been told.
Most permit reviews treat wetlands as a constraint. They are, in fact, infrastructure — already built, already paid for, already operating.
What a working wetland delivers (free)
- Recharges aquifers used for drinking water and agriculture
- Stores carbon at rates 2–10× upland forest, often higher in peat
- Buffers floods — USACE estimates ~$23B/yr in avoided U.S. flood damage
- Filters nutrients and sediments before they reach estuaries
- Supports nursery habitat for commercial fisheries
- Cools surface temperatures via evapotranspiration
What replaces it after a fill permit
- Impermeable surface — stormwater accelerates downstream
- Stored carbon vents within years of drainage
- Local heat-island effect from warm air exhaust
- New point-source discharge requirements
- "Mitigation banking" credits often miles away, ecologically dissimilar
- Decades-long restoration timeline if reversed
Mitigation banking — buying credits from a wetland restoration miles away to offset a fill — is the standard regulatory tool. It is not a like-for-like exchange. A coastal cypress strand and a restored stormwater pond are different things to a panther, an aquifer, and a hurricane.5
The heat & water tabletop demo.
You can show a city council in twenty minutes what a thousand-page environmental review obscures. Build the model, plug in a heat source, watch the wetland dry.
Tabletop wetland under load
A physical analog — small enough to fit on a folding table, vivid enough to end the meeting.
The kit
Glass aquarium, a slab of real wetland soil with native plants, a PC heatsink as the heat source, water, and a thermometer.
Watch it dry up
Heat from the sink drives evaporation. Steam rises as the wetland loses moisture rapidly — visibly faster than ambient.
Where does the water come from?
Wetland needs water. Heat makes it leave. Restricted airflow raises temperature. More heat means more loss. Now multiply by the campus footprint.
Show me the real numbers
Now require the developer to disclose actual measured water draw, peak hour kWh, and exhaust delta-T at their existing campuses. Not the design point. The measured.
How to read a data center permit.
Five questions to ask of any application. If a developer can't answer them in plain numbers, the application is not complete.
- 01
What is the measured water draw at your existing campuses?
"Design point" is a forecast. Measured is the meter. They are different numbers and the gap matters.
- 02
What is the peak-hour electrical load and who pays for the upgrades?
If the answer is "the utility will figure it out," the answer is "ratepayers."
- 03
What backup generation is on site and what is its emissions profile?
Diesel, gas turbines, and uninterruptible power systems all have permitting implications that are routinely understated at site approval.
- 04
What wetland acreage is being filled and what is the mitigation ratio?
Then ask: where is the mitigation site, what is its current condition, and on what time scale is it expected to deliver equivalent function?
- 05
What enforceable commitments survive a sale of the asset?
Hyperscale assets change hands. Every condition that lives only in a press release will not survive the closing.
Sources & further reading
- Lawrence Berkeley National Laboratory, 2024 United States Data Center Energy Usage Report — current load and 2030 projections (DOE).
- Mytton, D. (2021). Data centre water consumption. npj Clean Water 4, 11 — methodology for evaporative loss accounting.
- U.S. Environmental Protection Agency — WaterSense and Energy Star data center reporting.
- International Energy Agency — Electricity 2024, data center & AI section.
- U.S. Army Corps of Engineers — Section 404 permits and mitigation banking guidance; EPA Clean Water Act §404 overview.
- Nahlik, A. M., & Fennessy, M. S. (2016). Carbon storage in U.S. wetlands. Nature Communications 7 — carbon flux comparison.
- Costanza, R., et al. — recurring wetland ecosystem service valuations; basis for the ~$23B/yr U.S. flood-mitigation estimate widely cited by USACE and academic synthesis.
- Local note: for any campus near you, request the Title V air permit, the NPDES discharge permit, the §404 fill permit, and the utility's Integrated Resource Plan. They are public.
Citations are summary references. Specific projection ranges vary by methodology — the directional finding (sharp growth in load, water, and wetland fill pressure) does not.