Reservoir report

Maryland reservoirs & dams

Every documented dam and reservoir in Maryland — with normal storage capacity, dam height, max discharge, hazard classification, and drainage area. Sourced from USACE NID and state water-resource agencies.

Dams in Maryland

428

Total storage

901,552ac·ft

High-hazard dams

103

Updated

May 27

Open the Maryland reservoir layer on the map Every dam and reservoir filtered to Maryland on the interactive map.

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May

2026

Reservoir report

Maryland has numerous reservoirs and dams, with the largest being Loch Raven Reservoir, Prettyboy Reservoir, and Liberty Reservoir. The streams, rivers, and creeks that provide water to these reservoirs include the Gunpowder Falls, Patapsco River, and the North Branch Potomac River. The mountains and snowpack in the western part of the state are relevant as they contribute to the streamflow in these rivers. The hydrology in the area is influenced by the Chesapeake Bay and its water levels, which are affected by tidal cycles and precipitation. In recent years, Maryland has experienced drought conditions and record low streamflow levels, leading to water restrictions and conservation efforts. Seasonal trends include higher water levels in the spring due to snowmelt and increased precipitation, followed by lower levels in the summer and fall. Overall, reservoirs and dams play an important role in providing water to Maryland's population and supporting various industries, including agriculture and tourism.

Maryland at a glance

Storage, hazard, and history

How the Maryland dam inventory breaks down -- aggregate stats computed across every documented dam in the state.

Hazard classification

High103
Significant149
Low176

USACE downstream-consequence rating, not failure likelihood.

Notable dams

Tallest Jennings Randolph Dam 296 ft
Oldest Allen Town Pond (Allen Road) 1700
Total storage All Maryland dams 901,552 ac·ft

Built by decade

Most U.S. dams were built mid-20th century during the federal water-development era.

Full inventory

Maryland dams & reservoirs

Every documented dam in Maryland. Sortable by any column; quickly filterable by name. Numeric columns heat-mapped from light to deep based on value. Tap any dam for the full report.

Name	Year built	Normal storage	Dam height	Max discharge	Hazard	Drainage area
Prettyboy Dam	1936	60,100	155	24,500	High	80
Loch Raven Dam	1923	72,700	130	173,000	High	303
Liberty Dam	1953	132,000	175	100,148	High	164
Deep Creek Dam	1925	93,000	85	111,458	High	63
Brighton	1943	17,200	82	83,000	High	77
Warner Gap Hollow Dam	1902	246	65	6,800	High	2
Smithsburg Reservoir	1881	61	16	0	Significant	2
Greenbelt Dam	1936	206	22	2,000	High	1
Frostburg Reservoir	1990	1,410	46	22,188	High	12
Western Maryland 4h Center	1937	118	22	1,034	Low	3
Johnsons Pond	1936	900	23	8,400	Significant	42
Herrington Manor	1938	216	24	3,235	Low	6
Cash Lake Dam	1939	163	16	2,550	High	2
Savage River Dam	1952	20,000	184	97,200	High	105
Powellville Dam	1940	77	9	2,580	Low	32
Fishing Creek Dam	1925	150	58	15,634	High	7
Broad Creek Dam	1948	254	36	28,957	High	31
Emmitsburg Dam	1950	110	30	2,456	High	1
Indian Acres Of The Chesapeake Bay (Holly Drive)	1973	115	15	700	Low	1
T. Howard Duckett Dam	1953	17,000	139	108,526	High	132
Lake Linganore	1972	2,700	63	31,093	High	82
Little Falls Dam - Potomac River	1958	1,008	12	484,000	Low	11,430
Pecks Branch Dam (Ashburton)	1956	89	59	0	High	0
Urieville Dam (Augustine Herman Hwy)	1955	134	17	1,750	Low	9
Sassafras Mill Dam	1934	39	10	645	Significant	4
Camden Avenue Dam	1921	100	12	2,300	Low	12
St Marys River Watershed Site 1	1975	3,200	38	20,576	High	9
Wye Mills Dam	1682	302	20	4,930	Significant	10
Little Deer Creek Site 1	1958	24	45	930	Significant	1
Little Youghiogheny Site 7	1960	31	45	7,560	High	2
Little Youghiogheny Site 2	1962	17	35	2,720	High	1
Umbc Dam	1976	0	38	11,700	High	1
Little Deer Creek Site 2a (Mcknight/Rutledge)	1962	33	44	2,890	Significant	2
Little Youghiogheny Site 6 (Broadford)	1971	1,410	46	17,000	High	7
Gilbert Run Dam 1 (Trinity Church)	1964	480	41	6,100	Significant	8
Gilbert Run Dam 3 (Jameson Dam)	1964	205	37	8,900	High	4
Chesapeake Ranch Estates Dam (Chisolm Trail)	1965	1,534	46	7,250	High	3
Little Deer Creek Site 3	1962	37	45	3,200	Significant	2
Wheaton Regional Park Dam	1962	35	24	1,934	Significant	0
Greenbrier State Park Dam & Dike	1965	414	64	14,168	High	1
Little Youghiogheny Site 1	1964	23	33	5,450	High	1
Little Youghiogheny Site 3	1965	17	35	4,020	High	1
Lake Needwood	1965	600	65	25,652	High	13
Unicorn Branch Dam	1964	116	13	4,626	Significant	20
Smithville Dam (Possum Hill Road)	1980	140	14	2,282	Low	10
Great Falls Estate Dam	1963	34	34	160	Low	0
Lake Frank	1967	785	78	24,317	High	12
Wilde Lake Dam	1967	202	28	6,869	Significant	4
Mason-Dixon Water Supply Pond	1966	108	67	8,188	Low	1
Lake Whetstone Dam (Montgomery Village Avenue)	1966	167	36	2,730	Significant	3
Lake Walker Dam - Pond 1 (Montgomery Village Avenue)	1966	39	35	512	High	0
Little Youghiogheny Site 5	1968	42	41	13,500	High	3
Lake Nirvana Dam (Main Street)	1967	90	29	215	Significant	0
Meadow Run Dam	1969	410	25	800	High	2
Hunting Creek Dam	1969	771	79	33,400	High	7
Saefern Dam	1967	8	26	24	Low	0
Gilbert Run Dam 2 (Wheatley)	1968	579	37	3,190	Significant	3
Blairs Valley Dam	1968	486	34	4,150	High	3
Little Tonoloway Dam	1953	42	17	810	Low	3
Stancills Inc. Settling Pond	1976	57	26	1	Low	0
Cosca Regional Park Dam	1970	76	28	17,600	High	3
Burba Lake Dam	1927	·	16	·	Significant	1
Lake Allen Dam	1947	43	11	·	Low	5
Atkisson Reservoir	1942	928	56	·	High	44
Mezick Farm Pond	1974	33	16	186	Low	1
Jennings Randolph Dam	1981	94,700	296	193,000	High	263
Lower Lake Royer	1898	180	19	800	High	2
Rocky Gap Dam	1969	5,381	98	17,677	High	9
Lake Merle (Eaglehead Drive)	1971	141	44	1,500	Significant	1
Lake Anita Louise	1973	62	40	109	Low	0
Nagels Mill Pond	1860	91	16	1,600	Significant	6
Lake Marian (Woodridge Road)	1973	64	50	150	Low	1
Barton Reservoir	1968	4	31	2,660	Significant	1
Potomac River Dam #4	1869	7,300	20	1,000,000	Significant	5,900
Columbia Gateway Dam	1972	39	36	1,820	High	1
Big Millpond Dam	1900	72	9	502	Low	8
Contee Main Settling Pond	1973	8	41	5,500	High	1
Lake Arbor (Lake Arbor Way)	1971	155	38	667	High	1
Lake Serene (Edgewater Drive)	1971	69	29	1,110	High	0
Urbana	1963	36	25	1,567	Low	1
Parker Pond (N. Shumaker Drive)	1956	130	11	806	Low	9
Rewastico Pond (Athol Road)	1911	40	10	717	Low	10
Seneca State Park Dam (Seneca Creek Road)	1975	1,592	64	2,727	High	3
Lake Churchill (Wynnfield Drive)	1971	228	44	3,025	Low	1
Cranberry Branch Dam	1957	337	32	91	Significant	0
Lake Of The Pines (Tarnans Branch Crossing)	1981	18	22	1,040	Significant	1
Poolesville Public Golf Course	1953	118	25	220	Low	1
Shores Of Calvert Lower Dam	1972	52	15	300	Low	0
Don Pleasants Dam	1977	96	50	2,277	Significant	1
Carroll County Farm Museum Dam	1964	20	20	1,548	Significant	0
Hancock Sewage Lagoon	1963	38	8	340	Low	0
Conowingo	1928	301,400	94	1,135,552	High	27,077
Fairlee Lake	1828	121	20	2,000	Low	4
St. Pauls Millpond	1900	91	15	1,161	Significant	3
Priestford Hills	1974	37	24	170	Low	0
New Germany State Park Dam	1930	52	12	380	Low	2
Lake Bonnie	1850	103	14	2,600	Low	12
Lake Roland Dam	1861	1,000	42	41,190	High	37
Pikesville Reservoir Storage Tanks	2007	61	22	0	High	0
Guilford Reservoir Storage Tanks	1893	104	35	0	High	0
Lake Montebello	1880	1,260	30	0	High	0
Lake Ashburton Reservoir And Storage Tanks	1910	650	40	0	High	0
Druid Hill Lake Reservoir And Storage Tanks	1871	1,180	118	240	High	0
Montebello Waste Water Lake	1915	79	46	915	Low	0
Soil Conservation Service Lake (Soil Conservation Road)	1939	45	17	781	Low	3
Redington Lake Dam	1940	·	13	438	Low	2
Williston Mill Dam (Md 617 Old Harmony Road)	1936	180	18	1,660	Low	8
Lake Louise	1930	252	21	532	Significant	1
Mason Dixon Original Settling Pond	1966	286	52	44	Low	0
Cove Point Lng Main Dam	1974	547	74	172	Significant	0
North Creek Dam	1977	26	24	380	Low	1
Lake Jennifer	1963	32	15	27	Low	0
Allen Town Pond (Allen Road)	1700	96	8	825	Low	13
Galestown Millpond (Galestown-Reliance Road)	1972	115	9	711	Low	8
Lake Elkhorn	1974	225	26	9,912	High	4
Wheaton Branch Storm Water Management	1979	11	27	7,825	High	1
Industrial Dam (Blue Bridge)	1954	248	40	83,500	Low	628
Allen Pond (Nottinghill Drive)	1972	35	16	214	Low	0
St Clair Farm Pond	1968	52	18	10	Significant	1
Rising Sun Waste Water Lagoon	1964	78	10	1	Low	0
Beaglin Park Dam (Beaglin Park Drive)	1976	234	21	6,787	High	20
Hurlock Oxidation Ponds	1968	227	24	30	Low	0
Annapolis Reservoir	1920	70	15	430	Significant	3
Daniels Dam	1833	514	27	14,500	Low	266
Potomac Dam No. 5	1830	0	20	340,000	Significant	5,100
Piney Run Dam	1974	6,036	73	22,002	High	10
Court House Point Disposal Area	1968	120	7	390	Low	1
Pearce Creek Disposal Area	1968	3,720	40	0	High	1
Grove Point Disposal Area	1968	900	20	0	Low	0
Chesapeake City East Disposal Area, Bethel Road	1968	1,500	42	·	High	1
Chesapeake City West Disposal Area	1968	·	27	300	Low	0
Holton Pond Dam	1958	39	13	200	Low	1
Lake Kittamaqundi	1967	146	7	920	Low	28
Tuckahoe State Park Dam (Crouse Mill Road)	1975	26	14	6,500	Low	100
Heritage Harbour (Mastline Drive)	1974	46	34	300	Low	0
Lake Waterford Dam	1925	66	18	2,468	Significant	5
Lake Jenkins	1936	33	35	666	Low	3
Leonard Pond	1914	133	11	1,700	Low	14
Upper Lake Royer	1898	40	12	350	Low	2
Bohemia Mill (Old Telegraph Road)	1913	51	15	970	Low	5
Roeder Farm Pond	1974	23	12	31	Low	0
Camp Fretterd Miltary Reservation Dam	1967	53	24	151	Low	0
Chestertown Stablization Pond No. 1	1967	84	29	20	Low	0
Chestertown Stablization Pond No. 2	1967	48	32	20	Low	0
Bittinger Farm Pond	1968	49	17	121	Low	1
Damazo Pond	1975	63	22	40	Low	1
Bond Farm Pond	1973	94	17	77	Low	0
Goldberg Pond	1965	58	20	428	Low	1
Riggs Farm Pond	1988	66	24	107	Low	0
Hampstead Industrial Center Dam	1956	49	28	670	Low	0
Joseph A. Banks Swm Pond	1975	43	15	1,000	Low	0
Jones Lake Dam	1930	33	13	1,273	Low	43
Mc Allister Pond No. 1	1967	24	22	70	Low	0
Grande View Farms Community Pond	1969	49	22	204	Significant	1
Campus Hills Pond	1969	56	23	155	Low	0
Boyd Farm Pond	1958	29	28	788	Low	0
Owings Farm Pond	1967	46	16	1,850	Significant	1
Watts Farm Pond	1977	40	16	300	Low	0
Elgin Farm Pond	1965	35	14	81	Low	1
Talbot Country Club Pond (Country Club Drive)	1963	31	12	51	Low	0
Carpenter Farm Pond	1968	35	9	500	Low	2
Scull Farm Pond	1974	69	22	84	Low	1
Ledford Pond Dam	1975	42	30	207	Significant	1
Panagopulos Farm Pond	1974	82	20	90	Low	0
Myrtle Grove Lake	1965	88	14	100	Low	2
Easton Primary Sewage Lagoon	1962	144	15	20	Low	0
Easton Secondary Sewage Lagoon	1962	45	12	20	Low	0
Lake Ridge Community Pond Dam (Alta Drive)	1969	67	28	38	Significant	0
Running Hare Vineyard Lake	1970	51	20	205	Low	1
Oliver Company (Lower Pond)	1957	7	14	50	Significant	0
Foreman Branch Dam	1955	92	7	548	Low	7
Riley Mill Pond	1950	128	14	2,014	Low	3
Back Creek Dam (Old Telegraph Road)	1900	43	11	1,820	Low	7
Briar Ridge Farm Pond	1966	28	26	165	Low	0
Inspiration Lake	1950	72	40	118	High	0
Lake Placid Dam (Edison Park Drive)	1963	81	26	323	Significant	1
Kemp Farm Pond	1971	15	28	186	Low	0
Pocomoke City Sewage Lagoon No.1 (North Pond)	1972	37	10	10	Low	0
Pocomoke City Sewage Lagoon No. 2 (South Pond)	1972	39	10	10	Low	0
Coulbourn Mill Dam (South Division Street)	1947	21	12	638	High	6
Morris Mill Pond (South Division Street)	1947	34	12	665	High	5
Lake Walker Dam - Pond 2 (Russell Avenue)	1977	38	17	40	Low	0
Cove Point Lng Secondary Dam	1974	15	35	181	Significant	0
York Building Products Pond No. 5	1971	316	44	75	Low	0
York Building Products Pond No. 6	1971	122	30	2,626	Low	0
Crabbs Branch Swm Facility (Redland Road)	1983	32	27	4,200	High	1
Anderson Mill Pond (Pemberton Drive)	1900	39	11	169	Low	6
Riawakin Pond (Nanticoke Road)	1950	53	13	87	Low	4
Mill Creek Dam	1930	27	11	131	Low	3
Chambers Lake	1937	22	11	466	Significant	5
Sunshine Acres Pond	1981	19	26	169	Low	0
Elk Neck State Park Dam	1960	150	25	180	Low	1
Perryville Water Supply	1900	13	15	1,320	Significant	3
Eden Mill Dam	1917	12	18	1,549	Significant	85
Waterfront Greens Community Pond	1986	28	27	295	Low	0
Burnt Mills Dam	1930	38	23	12,285	Significant	27
Hall Creek Dam	1930	43	11	231	Significant	1
Laurel Lakes No 2 (Upper) Oxford Drive	1986	14	14	2,141	Low	2
Laurel Lakes No 1 (Lower)	1986	100	21	3,000	Significant	2
Koontz Run Reservoir Tanks	2015	10	21	0	High	2
Tower Hill Community Pond Dam (Tower Hill Road)	1975	15	18	22	Significant	3
Snell Estates	1979	47	14	130	Low	0
Lakeview Dam/Westlake Dam	1960	32	26	483	Low	0
Lonaconing Reservoir	1895	20	20	65	High	2
Westlake Village Lake 3	1984	7	11	2,170	Low	2
Stillpond Creek Dam	1963	122	14	2,224	Significant	4
Clair Peake Dam (Md 235)	1983	58	26	44	Low	0
Indian Creek Site 2	1983	0	20	10,988	High	2
Claiborne Gooch	1982	30	6	1,151	Low	2
Centennial Park Dam	1985	510	42	13,897	High	4
Hagerstown Municipal Pwr Plant Dam	1950	48	10	775	Low	176
Indian Creek Site 3	1983	0	25	9,385	High	2
Hagerstown City Park Lake (Key Street)	1920	50	10	37	Low	2
Midland-Gilmore Reservoir	1903	15	19	135	High	2
Newpage Westvaco Dam	1913	50	7	1,262	Low	404
Cohen Pond	1952	38	33	83	Significant	0
Little Seneca Dam	1984	13,050	99	73,292	High	21
Prince George Country Club Dam (Pleasant Prospect)	1982	350	22	8,049	High	3
Mitchell Pond #1 (Nanticoke Road)	1937	16	9	537	Significant	3
Dodd Farm Pond	1984	10	27	25	Low	0
Gunners Lake (Wisteria Drive)	1985	145	28	2,580	Significant	2
Avenel - Tpc Dam #3	1986	17	30	101	Low	0
Hexton Farms	1966	40	15	2,100	Low	3
York Bldg Products Settling Pond 9	1988	600	43	1	Significant	0
Chenoweth Farm Pond	1990	32	24	177	Low	0
Hallowell Swm Dam	1990	84	29	3,800	Low	1
Seven Oaks Swm Dam	1989	0	17	1,189	Low	1
Medford Quarry Wash Pond	1988	17	26	34	Significant	0
Columbia Creek Dam	1987	26	14	400	Low	1
York Bldg Products Settling Pond 10	1991	600	48	1	Significant	0
Russett Center Lower Dam / Pond #1	1990	1	34	1,300	Low	1
Jessup Prison Dam	1982	20	31	1,200	Significant	1
Lake Helene Dam	1950	1	27	253	High	0
Parker Farms Dam	1978	18	32	64	Low	0
Gbmc Pond	1993	1	13	296	Significant	0
Oaks Of Harford (Tollgate Road)	1984	0	43	600	Low	1
Summit Hall Park Dam	1993	1	14	1,000	High	0
Russett Center Upper Dam / Pond #2 (Ridgemere Crossing)	1990	0	27	686	Low	0
Platter Farm Pond	1968	16	22	133	Low	0
Woodmark Community Pond	1968	10	12	31	Significant	0
Reichs Ford Landfill Swm Dam	1995	0	39	14	Low	0
Old Loch Raven Dam	1875	150	20	14,000	Low	303
Railroad Branch Swm Pond	1990	5	25	6,314	High	0
Hunters Run Swm Dam	1996	0	30	3,000	Significant	0
Kurt Sherman Dam (Upper Pond)	1957	39	28	100	High	0
Hillen Road Water Supply Tank	1920	64	36	42	High	0
Milestone Swm Pond No. 4	1995	0	26	310	Low	0
Wyndemere Swm Pond	1995	0	13	1,443	Significant	0
Summerfield Swm Pond No. 1 (Chatsfield Way)	1994	0	23	800	High	1
Windgate Swm Dam 3 (Burtons Cove Way)	1994	1	23	270	Significant	0
Madison Hill Swm Pond 1 (Silk Tree Drive)	1994	1	18	385	Significant	0
Fedex Field Pond No. 1	1997	2	28	400	High	1
Montgomery College - Germantown Campus - Swm Pond	1987	5	21	263	Low	0
Holly Hills Section 4 Swm Pond 1	2001	0	26	4,500	Significant	1
North Laurel Park Swm Pond (Sewall Avenue)	1998	0	30	493	Significant	0
Teels Lake Dam	1961	48	11	2,570	Low	4
Rattlewood Golf Course	1975	24	31	10	Significant	0
Tower Oaks	1999	3	25	1,300	Low	0
Cabin Creek Mill Dam	1882	50	8	254	Low	6
Little Bennett Golf Course	1992	42	22	620	Low	0
York Bldg Products Settling Pond 11	1999	400	51	0	Significant	0
Rolling Green Community Pond	1965	29	22	950	Significant	0
Boxers Rest Farm Pond	1975	52	8	800	Low	2
Umstc Lower Dam (Curie Drive)	2001	68	38	1,700	Significant	0
Piedmont Water Supply Intake Dam	1911	40	8	·	Low	120
Brighton West Swm Pond	1975	0	16	9,406	Low	3
Marlton South Swm Dam	2000	3	24	150	Low	1
Riva Trace Community Pond	1985	12	15	40	Significant	0
Ferry Landing Woods Pond	1981	69	22	400	Low	0
Riley Mill Dam - Lower Pond	1950	15	14	30	Low	3
Calvert Gateway	2000	0	16	367	Significant	0
Richard Smith Dam	1970	16	9	1,425	Low	2
Highland Lake	1960	40	22	60	Low	0
Beechtree Dam	2002	267	43	2,500	Low	2
Falls Road Golf Course	1990	25	25	710	High	0
Victoria Station Community Lake	1986	100	27	98	High	0
Mays Chapel Reservoir	1965	80	20	0	High	0
Towson Reservoir Storage Tanks	2013	50	40	0	High	0
Cristal Global Hawkins Point Plant Settling Basins	1960	·	21	8	Low	0
Gudelsky Pond Dam	1987	11	20	840	High	0
Great Falls Dam, Lock No. 20	1850	·	8	·	Low	·
Eaton-Raimond Pond	1960	25	16	3,800	Low	1
Starkey Pond	1950	100	11	55	Low	0
Lake Largo Town Center Dam (Kings Way)	1973	·	27	477	Significant	0
York Bldg Products Settling Pond 12	2004	1,800	70	0	Significant	0
Heritage Glen Dam	2004	0	12	750	Significant	0
Big Meadows Farm Dam	1979	20	13	969	Low	1
Fairfield East Dam	2004	0	18	960	High	0
Tall Oaks Crossing (Peach Tree Lane)	1985	30	14	296	Significant	0
Shellman Farm Dam	1979	9	10	2,448	Low	3
Queensberry Drive Swm Pond	2001	0	19	2,095	Significant	0
Cloppers Mill West Pond F (Cricket Hill Drive)	1996	0	26	1,600	Significant	0
Great Star Drive Swm Dam	1997	·	20	·	Low	·
Cortland Manor Swm Dam	2006	0	15	2,930	Low	2
Prince Frederick Wwtp Pond 2	2002	100	65	0	Low	0
Hobbits Glen Golf Course Dam	1966	·	22	1,000	Significant	0
Johns Hopkins Bayview Campus Swm Pond	2004	13	20	166	Significant	0
Montgomery Auto Park Dam	1987	1	29	500	Low	0
Cecil Sand And Gravel Pond 6	2006	260	49	0	Significant	0
Shores Of Calvert Upper Dam (Rivershore Drive)	1972	20	25	125	Significant	0
Oakhurst Section 1 Swm Dam (Oakhurst Drive)	1998	·	12	·	High	0
Mason-Dixon Farms Irrigation Pond	1984	20	15	0	Low	0
Monocacy Boulevard Dam	2011	20	15	33	High	1
Laurel Lumber Dam	2007	1	12	383	Significant	0
Queen Annes Village Swm Pond No. 1	2007	1	20	754	Significant	0
Ritchie Hill Swm Pond	2008	·	15	856	Significant	0
Greenspring Quarry Dam	2007	0	16	4,206	Significant	1
Glen Elyn Lower Dam (Forest Glen Drive)	1975	9	22	170	Significant	0
Glen Elyn Upper Dam	1975	4	19	516	Significant	0
South River Colony Parcel A Swm Lake	1991	20	14	2,850	Low	0
Shipleys Crossing North Dam 1 (Galiot Dr)	2008	0	9	130	Significant	0
Shipleys Crossing North Dam 2 (Wherry Ct)	2008	0	14	200	Significant	0
York Bldg Products Settling Pond 13	2016	1,022	45	1	Significant	0
Village Of Scots Fancy Swm Pond (Starmount Lane)	1991	0	27	160	Significant	0
Chartwell Country Club Dam	2010	32	22	5,529	Significant	1
Snowden Pond	1947	48	21	420	Low	0
Ashton Community Pond Dam	1959	·	22	·	Significant	0
Chesapeake Bay Golf Club North East Dam	1990	17	25	320	Significant	1
Sunderland Railroad Embankment Pond	1850	16	25	600	Low	0
Woodlawn Railroad Embankment On Basin Run	1940	0	40	·	High	1
Martindale Pond	1975	·	20	56	Significant	0
Jessup Park Dam	2010	1	10	313	Significant	0
Velvet Hills South Swm Dam	1987	0	15	411	Significant	0
Pearce Creek Lake	1800	900	20	·	Low	·
Cherry Hill Park Dam	1986	3	13	244	Significant	0
Breton Bay Golf And Country Club Dam	1970	40	45	238	Significant	0
Dry Run Detention Dam And Culvert	1949	0	16	2,070	High	4
Roland Run Levee	1982	0	15	1	High	5
Willson Water Treatment Plant Levee	1927	·	30	·	Significant	·
Holly House Meadows Dam	1983	6	20	2,830	High	0
Bowie Gateway Swm Pond Dam	1992	6	28	910	Low	1
Gateway Village Pond	1988	4	19	884	Significant	0
Lake Karylbrook Community Pond (Karen Drive)	1990	90	30	·	Significant	0
Montgomery College - Rockville Campus - Swm Dam	1965	5	14	1,390	Significant	0
York Building Products Pond No. 7 Dam	1971	122	30	2,626	Low	0
Painters Mill Levee	1989	·	14	·	Significant	·
Queensberry Drive Playground Dam	1981	30	28	163	Significant	0
Cherryvale Neighborhood Park Pond	1960	4	10	38	Significant	0
Crofton Farms Regional Swm Pond	1998	0	15	·	Low	0
Bowie Town Center Lake	1990	37	20	·	High	0
Collington Life Care Center Lake	1986	30	25	105	Low	0
Umbc Central Campus Dam	1975	2	10	·	Significant	0
Twin Lakes Upper Pond (Hoile Lane)	1970	10	15	204	Significant	0
Montgomery Airpark Dam (Asset 11568)	1985	2	22	871	High	0
Fullerton Reservoir Tanks	2020	61	15	·	High	·
Rolling Hills Swm Pond	1982	0	15	·	High	0
Chadswood Swm Pond (Cross Laurel Drive)	1981	·	20	·	Significant	0
Tinkers Creek Regional Swm Pond No. 8	1991	16	18	247	Significant	0
Lutheran Village At Millers Grant Pond 1 (Vals Lane)	2015	0	18	300	Significant	0
Roberts Field Basin 1 (North Woods Trail At Boxwood)	1992	14	25	151	Significant	0
Roberts Field Basin 2 (North Woods Trail Near Trophy Drive)	1992	0	22	716	Significant	0
Roberts Field Basin 3 (Sycamore Drive)	1992	0	18	219	Significant	0
Mary Lee Lane Swm Dam	1985	·	11	·	Significant	0
Town Mall Swm Pond	1985	0	12	296	Significant	0
Neelsville Estates Dam	1995	14	15	·	Significant	0
Collington Facility 9 Dam (Dunwood Crossing Dr)	1990	68	21	247	Significant	1
Stonegate Swm Dam (Cherryfield Road)	2003	24	25	730	Low	0
Adventure Sports Center Pond	2007	20	27	150	Low	0
Northridge Swm Pond (Quisinberry Way)	1989	49	28	494	Significant	0
Plumgar I Regional Swm Dam	1989	41	24	·	Low	0
Germantown Estates Regional Facility Swm Dam (Steeple Road)	1995	76	22	·	Low	0
Norris Dam	1990	84	10	·	Low	0
Valley Mall Expansion Swm Dam	1987	8	19	444	Low	0
Wildewood Community Dam	1989	76	30	1,100	Low	1
Collington Facility 14 Swm Dam	1992	0	16	·	Low	0
Karington Swm Dam	2007	86	15	163	Low	11
Carroll County Air Business Center Swm Pond	1992	52	14	208	Low	0
Spring Ridge Swm Pond No. 4a	1994	6	16	400	Low	0
Greenspring East Swm Pond No. 3 (Stream Crossing Road)	1995	16	34	163	Low	0
Pleasant Hills Swm Dam (Gentlebrook Road)	1988	109	17	700	Low	0
Lake Varuna (Lakelands Drive)	1992	62	18	·	Low	0
Seneca Meadows Swm Dam (Seneca Meadows Pkwy)	1994	0	17	619	Low	1
Martin Luther King Jr. Park Dam	1978	16	27	22	Low	0
Park Retreat Swm Pond	2013	3	20	100	Low	0
Rabbitt Road Swm Pond	1981	0	23	2,700	Low	1
Linden Chapel Road Swm Dam	1989	·	16	·	Significant	0
Cecil Sand And Gravel Pond 7	2017	255	24	1	Significant	0
Frederick Research Park Lot 4 Swm Pond	1990	5	20	6,745	Significant	1
Dobbin Road Swm Pond	1987	26	36	183	Significant	0
Bwi Pond B12	1995	0	21	1,249	Significant	0
Victory Farms	1973	0	23	2,000	Significant	1
Greencastle Lakes (Ballenger Drive)	1965	7	36	273	Low	0
Strawberry Fields	1985	10	20	420	Significant	0
Summit Lake Church Camp Dam	1930	20	15	5	Low	0
Mt Airy Park-N-Ride Swm Pond	1972	0	15	300	Significant	0
Upper Potomac Industrial Park Levee	2005	0	8	0	High	0
Henson Creek Flood Control Dam #17	1992	0	22	2,428	Significant	0
Diversified Lane Pond Dam	1992	·	8	·	Significant	·
Glenmar Pond 2 Dam	1984	·	3	·	Significant	·
Waiting Springs Swm Pond	1971	1	12	461	Significant	0
Gerwig Lane Swm	1980	·	·	·	Significant	·
Volvo Hagerstown Swm	1961	0	7	·	Significant	0
Allison Street Levee (Mt. Ranier)	1988	·	15	·	High	·
Frost Pond (Mlk Jr. Hwy)	1988	0	27	·	Significant	0
Manchester Farm Regional Swm Pond Dam	1996	65	21	2,350	Significant	0
Mt. Soma Reservoir	2018	288	61	48	High	0
Stoneleigh Community Pond (Stoneleigh Court)	1978	·	24	·	Significant	0
Catonsville Community Park Regional Swm Pond Dam (Ba-359)	1985	0	21	1,100	High	0
Montgomery Run Swm Pond 1 (Montgomery Run Road)	1990	·	20	·	Significant	·
Country Meadows Swm Pond	1988	1	17	200	Significant	0
New Bald Eagle Road Swm	2006	1	44	250	High	0
Guilford Road Dam	·	·	·	·	Significant	·
Cox Creek Dmcf	1960	3,500	36	·	Low	0
Masonville Dmcf	2005	3,500	18	·	Low	0
Point Of Rocks Dam	1990	3	14	1,120	Significant	0
West Farm Regional Swm Pond	1987	65	25	3,742	Significant	1
Whiskey Bottom West Swm	1978	0	10	·	Low	·
Amtrak Railroad Culvert 100.18	1888	0	24	125	Significant	0
Beaver Dam Run Levee	1970	·	15	·	Significant	·
Turkey Branch Levee (Asset 17673,17674 And 17675)	1975	0	12	·	Significant	·
Montclair Manor Levee (Asset 14616)	2004	0	15	·	Significant	·
Harry S. Truman Pkwy Park N Ride Swm Pond	1987	1	14	·	Significant	21
Perrywood (Water Fowl Way)	2003	6	19	1,395	Low	1
Perrywood (Manor House Drive)	1984	10	16	126	Significant	0
Junction Industrial Park	1984	·	18	793	High	74
Warfield Range Dam (Hunters Way)	1980	0	20	·	Significant	·
Ashcroft Drive - Woodbridge Pond	·	·	20	·	High	·
Van Dusen Road	1988	0	23	·	Significant	·
Vista Business Park	2020	0	13	2,875	High	0
Summit Creek - Mount Auburn Dr	2000	·	15	·	High	·
Md Route 104 Swm Pond (Sha Bmp 130077)	1990	·	17	·	Significant	0
Jennifer Road Swm Route 50 And Route 2 (Sha Bmp 020259)	1985	26	47	·	Significant	·
Chevy Chase Lakes	1900	·	24	·	Significant	0
Hanson Oaks Swm (Bmp Structure 1558-002)	1900	10	20	·	High	0
Aragona Village	1991	·	21	·	High	0
Summerfield Swm Pond No. 2	·	0	15	·	High	0
New Mark Commons Community Lake	1966	30	15	·	Significant	0
Banneker Regional Pond	2006	0	15	·	Significant	·

Reservoir FAQ

About Maryland dams & reservoirs

Where does the Maryland dam data come from?

The U.S. Army Corps of Engineers National Inventory of Dams (NID) plus state water-resource agencies. Snoflo joins these public records with live USGS streamgauge readings downstream where available. The NID is the canonical federal dam registry.

What does Hazard Potential mean?

USACE classifies every dam by what would happen if it failed: Low (no loss of life expected, minimal economic damage), Significant (no loss of life but economic, environmental, or lifeline damage), High (loss of life expected). It's a downstream-consequence rating, not a likelihood of failure.

What is Normal Storage in acre-feet?

The volume of water the reservoir holds at its normal operating level, measured in acre-feet. One acre-foot is about 325,851 gallons or 1,233 cubic meters — the amount needed to cover one acre to a depth of one foot.

Why are some Maryland dams missing storage or height data?

USACE NID records can have gaps for small or older dams that pre-date federal reporting requirements. Snoflo surfaces whatever the canonical record contains. If a dam you care about has incomplete data, contact the operating agency or USACE for updates.

Can I see live water levels?

Yes — tap any dam name to open its detail page, which pulls live storage data from USGS streamgauges or operating-agency feeds where available. Historical levels and seasonal averages are also shown.

Why does Maryland have so many dams?

The U.S. has over 90,000 dams — most built between 1930 and 1980 during the federal water-development era. Maryland's count reflects a combination of agricultural irrigation needs, flood control, hydropower, and recreation. The "Built by decade" chart above shows the timeline.