Seattle City Council members introduced a 365-day emergency moratorium on large data centres on 30 April 2026, the day after Maine's House failed to override Governor Mills's veto. The proposed ordinance bans any new or expanded electrical load above 10 MW for a full year, with a possible six-month extension if the council chooses to renew it.
The trigger was four developers asking Seattle City Light, the city's publicly-owned electricity utility, to power five facilities totalling 369 MW, roughly the consumption of 300,000 Seattle homes. Four requests, one week, one freeze. At least two of those developers withdrew their plans before the ordinance came up for a vote. Mayor Katie Wilson announced on 1 May that she was identifying initial executive steps, language that operators read as a signal the freeze will harden, not soften, in committee.
Seattle is the first major American city to pull the moratorium lever at the speed of the load request that prompted it, and the legal architecture matters. State moratoriums are creatures of legislative committees, governor sign-offs, and trade-association lobbying budgets; municipal moratoriums are creatures of council majorities and utility-board agendas. The route from Microsoft's Quincy campus, the AWS US-West-2 cluster, and the Tacoma greenfield queue all run through Seattle City Light's interconnection process, and that process is now unavailable until at least 30 April 2027. For developers running Pacific Northwest siting plans on a 36 to 48 month timeline, a year-long freeze inside that window is a forced relocation of capital, not a delay.
