Dam safety by state

Dams in Oregon

By Michael Flynn, PE · water resources & dam safety engineer

Oregon has 884 dams in the National Inventory of Dams, of which 173 are classified high hazard — and only 1.2% lack an emergency action plan, one of the better records nationally. Inventory, condition and hazard data computed from the USACE extract stamped 2026-8-28, with the governing law cited below.

What this page is

Verified inventory data and a pointer to where Oregon's dam safety law lives. It deliberately does not summarise what that law requires — those requirements have not been checked against current primary sources for Oregon, and a stale paraphrase of a dam safety statute is worse than none.

For a state written up in full, see North Carolina.

Oregon by the numbers

Oregon dam inventory — NID extract 2026-8-28
MeasureCountNational rank
Total dams88433rd
High hazard17330th
— with an EAP recorded171
— with no EAP recorded240th largest gap
— EAP not required0
High hazard rated Poor18
High hazard rated Unsatisfactory13

31 of Oregon's high-hazard dams are rated Poor or Unsatisfactory (17.9% of them).

Governing law

Oregon's dam safety laws that dated to 1929 have been repealed and replaced with a new law that will be fully operative on July 1, 2020. As a new law, it awaits specific Chapter and number references by Legislative Counsel to replace Oregon Revised Statutes (ORS) 540.350 ยง 540.390, very likely in the same Chapter.

Citation compiled from the ASDSO 2020 summary of state dam safety laws and checked to refer to Oregon. It tells you where the law lives, not what it currently says: statutes get amended and section numbers get renumbered. Read the current text before relying on it, and contact the Oregon dam safety program for a determination that binds.

Counties with the most dams

Oregon dams by county — NID extract 2026-8-28
CountyDamsHigh hazardPoor/Unsat.
Malheur71109
Harney6004
Jackson56216
Lake4931
Douglas47173
Clackamas4691
Klamath4540
Polk4225
Baker4130
Washington4030
Yamhill4020
Marion4030

Where to go for Oregon's requirements

This page does not summarise what Oregon law requires. These do, or will point you at someone who can:

How Oregon compares

Nationally, 2,476 of 17,049 high-hazard dams have no emergency action plan on record. Oregon accounts for 0.1% of that gap. Full rankings, method and the downloadable dataset are on the national EAP gap page.

National EAP Gap Data →
All states ranked, with CSV
A State Written Up in Full
North Carolina: classification, permits, EAPs
Dam Safety Calculators
Breach, spillway, seepage, stability

Data source. Computed from the U.S. Army Corps of Engineers National Inventory of Dams national extract, stamped 2026-8-28. NID reflects what state and federal programs have reported to USACE; an "EAP Prepared: No" flag means no plan is recorded rather than proof that none exists.

Monthly engineering case studies

One real stormwater, dam, or hydraulics design problem per month, with the math worked out and the gotchas called out. No tutorials, no fluff.

Free. Unsubscribe anytime. Privacy.