Oldest Dams in Maryland

Maryland has 418 dams with recorded construction dates. The oldest dates to 1682 — 344 years ago. Many of Maryland's oldest dams were built as colonial-era mill dams, powering early industry along rivers and streams. Older dams require particular attention for safety, as many were built before modern engineering standards.

#	Dam	County	Year Built	Age	Height (ft)	Hazard	Condition
1	Wye Mills Dam	Queen Anne's	1682	344 yrs	20	Significant	Fair
2	Allen Town Pond (allen Road)	Somerset	1700	326 yrs	8	Low	Fair
3	Higgins Millpond	Dorchester	1801	225 yrs	9	Low
4	Fairlee Lake	Kent	1828	198 yrs	20	Low	Poor
5	Potomac Dam No. 5	Washington	1830	196 yrs	20	Significant	Not Available
6	Daniels Dam	Baltimore	1833	193 yrs	27	Low	Fair
7	Sunderland Railroad Embankment Pond	Calvert	1850	176 yrs	25	Low	Poor
8	Lake Bonnie	Caroline	1850	176 yrs	14	Low
9	Great Falls Dam, Lock No. 20	Montgomery	1850	176 yrs	8	Low
10	Nagels Mill Pond	Caroline	1860	166 yrs	16	Significant	Fair
11	Lake Roland Dam	Baltimore	1861	165 yrs	42	High	Fair
12	Potomac River Dam #4	Washington	1869	157 yrs	20	Significant	Not Available
13	Druid Hill Lake Reservoir And Storage Tanks	Baltimore City	1871	155 yrs	118	High	Poor
14	Old Loch Raven Dam	Baltimore	1875	151 yrs	20	Low	Not Rated
15	Lake Montebello	Baltimore City	1880	146 yrs	30	High	Fair
16	Smithsburg Reservoir	Washington	1881	145 yrs	16	Significant	Fair
17	Amtrak Railroad Culvert 100.18	Baltimore City	1888	138 yrs	24	Significant	Fair
18	Guilford Reservoir Storage Tanks	Baltimore City	1893	133 yrs	35	High	Satisfactory
19	Lonaconing Reservoir	Allegany	1895	131 yrs	20	High	Poor
20	Upper Lake Royer	Washington	1898	128 yrs	12	Low	Fair
21	Lower Lake Royer	Washington	1898	128 yrs	19	High	Fair
22	Perryville Water Supply	Cecil	1900	126 yrs	15	Significant	Poor
23	Back Creek Dam (old Telegraph Road)	Cecil	1900	126 yrs	11	Low	Not Rated
24	St. Pauls Millpond	Kent	1900	126 yrs	15	Significant	Poor
25	Hanson Oaks Swm (bmp Structure 1558-002)	Prince George's	1900	126 yrs	20	High	Poor
26	Anderson Mill Pond (pemberton Drive)	Wicomico	1900	126 yrs	11	Low	Poor
27	Big Millpond Dam	Worcester	1900	126 yrs	9	Low	Fair
28	Warner Gap Hollow Dam	Washington	1902	124 yrs	65	High	Unsatisfactory
29	Midland-gilmore Reservoir	Allegany	1903	123 yrs	19	High	Poor
30	Lake Ashburton Reservoir And Storage Tanks	Baltimore City	1910	116 yrs	40	High	Not Rated
31	Piedmont Water Supply Intake Dam	Garrett	1911	115 yrs	8	Low	Not Rated
32	Rewastico Pond (athol Road)	Wicomico	1911	115 yrs	10	Low	Fair
33	Newpage Westvaco Dam	Allegany	1913	113 yrs	7	Low	Fair
34	Bohemia Mill (old Telegraph Road)	Cecil	1913	113 yrs	15	Low	Not Rated
35	Leonard Pond	Wicomico	1914	112 yrs	11	Low	Fair
36	Montebello Waste Water Lake	Baltimore City	1915	111 yrs	46	Low
37	Eden Mill Dam	Harford	1917	109 yrs	18	Significant	Fair
38	Annapolis Reservoir	Anne Arundel	1920	106 yrs	15	Significant	Fair
39	Hillen Road Water Supply Tank	Baltimore City	1920	106 yrs	36	High	Satisfactory
40	Hagerstown City Park Lake (key Street)	Washington	1920	106 yrs	10	Low	Satisfactory
41	Camden Avenue Dam	Wicomico	1921	105 yrs	12	Low	Fair
42	Loch Raven Dam	Baltimore	1923	103 yrs	130	High	Satisfactory
43	Lake Waterford Dam	Anne Arundel	1925	101 yrs	18	Significant	Satisfactory
44	Fishing Creek Dam	Frederick	1925	101 yrs	58	High	Unsatisfactory
45	Deep Creek Dam	Garrett	1925	101 yrs	85	High	Fair
46	Burba Lake Dam	Anne Arundel	1927	99 yrs	16	Significant	Unsatisfactory
47	Willson Water Treatment Plant Levee	Washington	1927	99 yrs	30	Significant	Fair
48	Conowingo	Cecil	1928	98 yrs	94	High	Satisfactory
49	Hall Creek Dam	Cecil	1930	96 yrs	11	Significant	Unsatisfactory
50	Mill Creek Dam	Dorchester	1930	96 yrs	11	Low

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