Scour-Critical Bridges in Maine

Maine has 141 bridges rated scour-critical by the Federal Highway Administration. These bridges have foundations that are unstable or at risk of undermining during flood events. Scour-critical doesn't mean a bridge is about to collapse — it means extra monitoring and countermeasures are in place — but these structures are priorities for repair or replacement.

How this ranking works

This state list filters to NBI scour ratings 0 through 3, then sorts by average daily traffic. It is intended to show flood-vulnerability exposure, not to label any bridge as currently unsafe.

Bridge	County	Scour Rating	Daily Traffic	Condition
Bar Harbor RD over Mt Desert Narrows	Hancock	3 — Serious	15,122	Fair
Main ST over Damariscotta River	Lincoln	3 — Serious	14,450	Fair
Route 1 over Cousins River	Cumberland	3 — Serious	9,550	Poor
Mercer RD over Sandy River	Franklin	3 — Serious	8,124	Fair
Mayville RD over Bear River	Oxford	3 — Serious	5,738	Fair
Military RD over Three Brook Stream	Aroostook	3 — Serious	5,030	Fair
Route 1 over Pleasant River	Washington	3 — Serious	4,408	Fair
Main ST over Mill Stream	Knox	3 — Serious	4,273	Fair
Main ST over Mill Stream	Knox	3 — Serious	4,273	Fair
New County RD over Cooks Brook	York	3 — Serious	4,258	Fair
Limestone RD over Aroostook Riv Abandd Rr	Aroostook	3 — Serious	3,620	Poor
Mapleton RD over N Br Presque Isle Stream	Aroostook	3 — Serious	3,581	Fair
Station ST over Aroostook River	Aroostook	3 — Serious	3,210	Fair
Main ST over Wilson Stream	Franklin	3 — Serious	2,854	Poor
Milbridge RD over Narraguagus Rv	Washington	3 — Serious	2,493	Poor
Station RD over W Br Molunkus Stream	Penobscot	3 — Serious	2,071	Fair
Main ST over Wapsaconhagan	Washington	3 — Serious	1,936	Fair
W Main ST over Moose Pond Outlet	Oxford	3 — Serious	1,614	Fair
Granite ST over Millinocket Stream	Penobscot	3 — Serious	1,548	Poor
Sumner RD over E Branch Nezinscot River	Oxford	3 — Serious	1,503	Fair
North ST over E.branch Sebasticook R.	Penobscot	3 — Serious	1,335	Fair
River RD over Carrabassett Stream	Kennebec	3 — Serious	1,331	Poor
Warren Hill RD over Indian Stream	Somerset	3 — Serious	1,310	Fair
Scotland Bridge RD over York River	York	3 — Serious	1,310	Fair
Houlton RD over Dyer Brook	Aroostook	3 — Serious	1,308	Fair
Main ST W over Billy Brook	Oxford	3 — Serious	1,195	Poor
Mill Hill RD over Martin Stream	Androscoggin	3 — Serious	1,193	Poor
Waugan RD over Wilson Stream	Kennebec	3 — Serious	1,182	Poor
Sebago RD over Quaker Brook	Cumberland	3 — Serious	1,180	Fair
Grand Lake Stream over Huntley Brook	Washington	3 — Serious	1,157	Good
River RD over Pooler Brook	Somerset	3 — Serious	1,068	Fair
Washington ST over Lubec Narrows	Washington	3 — Serious	992	Poor
Weld RD over Temple Brook	Franklin	3 — Serious	935	Fair
W Corinth RD over Kenduskeag Stream	Penobscot	3 — Serious	927	Fair
Bridge RD over Penobscot River	Penobscot	3 — Serious	905	Fair
Peltoma Av over Sebasticook River	Somerset	3 — Serious	876	Fair
Drews Lake RD over S. Br. Medux. R.	Aroostook	3 — Serious	840	Fair
Bridge ST over Kennebec River	Somerset	3 — Serious	833	Fair
Rawson Av over Megunticook River	Knox	2 — Critical	830	Poor
US Highway 2 over Molunkus Stream	Aroostook	3 — Serious	802	Poor
Milton RD over Baker (peterson) Brook	Oxford	3 — Serious	784	Fair
Stetson RD over French Stream	Penobscot	3 — Serious	779	Fair
East School ST over Messalonskee Str	Kennebec	3 — Serious	767	Poor
Douty Hill RD over Black Stream	Piscataquis	3 — Serious	738	Poor
Maxcys Mills RD over W Br Sheepscot River	Kennebec	3 — Serious	735	Fair
Poland Range RD over Chandler Brook	Cumberland	3 — Serious	730	Poor
Camden RD over ST George River	Knox	3 — Serious	720	Fair
Lang Hill HWY over Marsh Stream	Waldo	3 — Serious	704	Fair
Roxbury Pond RD over Black Brook	Oxford	3 — Serious	702	Fair
Woodville RD over Ebhorse Stream	Penobscot	3 — Serious	666	Fair
W Kingfield RD over Alder Stream	Franklin	3 — Serious	632	Fair
Frenchville RD over Alder Brook	Aroostook	3 — Serious	630	Fair
Patrick Town RD over Sheepscot River	Lincoln	3 — Serious	623	Fair
Kennebec River RD over Martin Stream	Somerset	3 — Serious	599	Poor
ST RTE 160 over Ossipee River	York	3 — Serious	570	Fair
Stagecoach RD over Piscataquis River	Piscataquis	3 — Serious	543	Fair
Walton RD over Lovejoy Pond Outlet	Kennebec	3 — Serious	540	Fair
Grimes RD over Little Madawaska Rv	Aroostook	3 — Serious	538	Fair
E Ridge RD over Olamon Stream	Penobscot	3 — Serious	533	Fair
N Village RD over Ogunquit River	York	3 — Serious	530	Fair
Greanleaf Av over Penneseewassee Stream	Oxford	3 — Serious	520	Fair
River RD over Ossipee River	York	3 — Serious	500	Fair
Depot Street over Stevens Brook	Cumberland	3 — Serious	435	Poor
Avon Valley RD over Valley Brook	Franklin	3 — Serious	429	Fair
Military RD over Wytopitlock Stream	Aroostook	3 — Serious	384	Fair
Castonguay RD over Violette Brook	Aroostook	2 — Critical	380	Poor
W Freeman RD over Bean Brook	Franklin	3 — Serious	370	Fair
Horne ST over Pennesseewassee Stream	Oxford	2 — Critical	352	Poor
Swetts Bridge RD over Middle Br Mousam Rivr	York	3 — Serious	352	Fair
Sodom RD over Crooked River	Oxford	3 — Serious	351	Fair
S Shore DR over South Bog Stream	Franklin	3 — Serious	308	Fair
Boyle RD over Great Works River	York	3 — Serious	294	Fair
Bald Mountain RD over Moosehorn Creek	Hancock	2 — Critical	291	Poor
Old Houlton RD over Three Brooks	Aroostook	3 — Serious	262	Fair
Limestone ST over Otter Brook	Aroostook	3 — Serious	260	Poor
Pierce RD over Prestile Stream	Aroostook	3 — Serious	250	Fair
Aroostook RD over Little Molunkus Stream	Aroostook	3 — Serious	241	Fair
Old County RD N over Shepards River	Oxford	2 — Critical	240	Poor
Somerville RD over Sheepscot River	Lincoln	3 — Serious	228	Fair
Diamond Hill RD over Little River	York	3 — Serious	220	Poor
Choate RD over W Br Sheepscot River	Kennebec	3 — Serious	206	Poor
Sweetser RD over Chandler Brook	Cumberland	3 — Serious	203	Fair
Long Falls Dam RD over Michael Brook	Somerset	3 — Serious	200	Poor
Milton RD over Concord River	Oxford	3 — Serious	199	Fair
Stevens RD over Sandy Stream	Waldo	3 — Serious	192	Fair
Evans Notch RD over Stony Brook	Oxford	3 — Serious	191	Fair
Main RD over Cold River	Oxford	3 — Serious	186	Fair
Pleasant Pond RD over Pleasant Pond Stream	Somerset	3 — Serious	180	Poor
Island Av over Penobscot River Overflow	Penobscot	2 — Critical	177	Poor
Island Avenue over Penobscot River Overflow	Penobscot	2 — Critical	158	Poor
Center ST over E Br Sebasticook R	Penobscot	3 — Serious	158	Fair
Seboeis RD over Seboeis Stream	Penobscot	3 — Serious	154	Fair
Long Falls Dam RD over Pond Stream	Somerset	3 — Serious	145	Poor
Inv 2100307 RD over Little Nesowadnehunk	Piscataquis	3 — Serious	144	Fair
Webster RD over Wilson Stream	Franklin	3 — Serious	140	Fair
Frenchtown RD over Intervale Brook	Piscataquis	3 — Serious	133	Poor
Grover Bridge RD over Webb River	Franklin	3 — Serious	129	Poor
Mace RD over Mcgurdy Stream	Franklin	3 — Serious	127	Poor
Guzzle RD over West Bay Stream	Hancock	2 — Critical	126	Poor
Blake RD over Limestone Stream	Aroostook	3 — Serious	120	Poor
Berry Mills RD over Webb River	Franklin	3 — Serious	117	Fair
Silvers Mills RD over French Mills Brook	Piscataquis	3 — Serious	103	Poor
Town Line RD over W Br Mattawamkeag Rv	Aroostook	3 — Serious	90	Fair
Lane Road over Fillibown Brook	Franklin	3 — Serious	90	Poor
Tannery Bridge RD over Lemon Stream	Somerset	3 — Serious	90	Poor
Station RD over Mill Stream	Washington	3 — Serious	84	Poor
Webber Pond RD over Kezar River	Oxford	2 — Critical	83	Poor
Fairgrounds LN over ST George River	Knox	3 — Serious	80	Fair
Jordan RD over No Name Brook	Androscoggin	3 — Serious	78	Poor
Sawyer Notch RD over Sawyer Brook	Oxford	3 — Serious	72	Fair
East Dover Road over Alder Brook	Piscataquis	3 — Serious	72	Good
Hotel DR over Kingsbury Stream	Piscataquis	3 — Serious	72	Fair
Crane RD over W Br Kenduskeag	Penobscot	2 — Critical	71	Poor
Reeds Mill RD over Whinship (conant) Stream	Franklin	3 — Serious	66	Fair
Desmond RD over Alder Stream	Piscataquis	3 — Serious	63	Poor
Mapledale LN over Greeley Brook	Oxford	3 — Serious	62	Poor
Ridlon RD over Little River	York	3 — Serious	60	Poor
Upper Long Pond RD over Moosehorn Stream	Hancock	3 — Serious	58	Fair
Smith Farm RD over Pleasant River	Oxford	3 — Serious	54	Good
Millet RD over Kenduskeag Stream	Penobscot	2 — Critical	54	Poor
Red Bridge RD over Carrabasset Str	Somerset	2 — Critical	52	Poor
Madore RD over Hammond Brook	Aroostook	3 — Serious	50	Fair
Fern DR over Kezar River	Oxford	3 — Serious	50	Poor
Frog Aly over Old Course Of Saco River	Oxford	3 — Serious	50	Fair
Meadow Brook Bridg over W Branch Pleasant River	Oxford	3 — Serious	41	Fair
Jordan Mills RD over Mattaseunk Stream	Penobscot	3 — Serious	41	Poor
Andrews RD over Salmon Stream	Piscataquis	3 — Serious	41	Fair
Smarts Pond RD over Little Ossipee River	York	3 — Serious	40	Fair
Lohnes Farm RD over Beaver Brook	Oxford	2 — Critical	37	Poor
Penobscot Av over Run-around Stream	Penobscot	3 — Serious	31	Fair
Beech Hill RD over Saddleback Stream	Franklin	3 — Serious	30	Fair
Peavey Town RD over Sheepscot River	Waldo	3 — Serious	29	Poor
Main ST over Cascade Str	Franklin	3 — Serious	26	Poor
Cushman RD over Bowley Brook	Franklin	3 — Serious	26	Poor
Pease Bridge RD over Carleton Stream	Piscataquis	3 — Serious	21	Poor
Burnt Brow RD over Captain Ambrose Bear Str	Aroostook	3 — Serious	20	Fair
Ripley Corner RD over St. George River	Waldo	0 — Bridge closed	14	Poor
Fernald RD over Kenduskeag Str	Penobscot	3 — Serious	10	Good
Mountain RD over Blackstone Brook	Piscataquis	3 — Serious	10	Good
East Branch Road over Big Spring Brook	Penobscot	0 — Bridge closed	2	Poor
Inv 2100793 RD over Nesowadnehunk Stream	Piscataquis	3 — Serious	0	Fair