Reservoir report

Arizona reservoirs & dams

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

Dams in Arizona

371

Total storage

33,640,982ac·ft

High-hazard dams

160

Updated

May 20

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

Open the map →

May

2026

Reservoir report

Arizona relies heavily on reservoirs and dams to store and manage its limited water resources. Major reservoirs in the state include Lake Mead, Lake Powell, Roosevelt Lake, Apache Lake, and Lake Havasu. These reservoirs are fed by streams, rivers, and creeks such as the Colorado River, Salt River, Verde River, and Gila River. The hydrology of the area is heavily influenced by snowpack in the surrounding mountains, particularly the Rocky Mountains and the Sierra Nevada Mountains. Record low levels have been observed in Lake Mead and Lake Powell due to drought conditions in recent years, leading to concerns about water supply for agriculture, industry, and municipalities. Seasonal trends show that the majority of precipitation occurs during the winter months, while the summer months are typically dry and hot. Water management in Arizona is a complex issue, with competing demands for water use and limited resources available.

Arizona at a glance

Storage, hazard, and history

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

Hazard classification

High160
Significant39
Low166
Unknown6

USACE downstream-consequence rating, not failure likelihood.

Notable dams

Tallest Glen Canyon 710 ft
Oldest Walnut Canyon 1881
Total storage All Arizona dams 33,640,982 ac·ft

Built by decade

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

Full inventory

Arizona dams & reservoirs

Every documented dam in Arizona. 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
Cave Creek	1923	0	44	20,000	Low	162
Lyman Dam	1912	30,600	60	15,000	High	790
Lower Goldwater	1923	271	67	·	High	3
River Reservoir #3	1896	2,146	58	24,000	High	34
Nelson	1890	770	34	2,200	Low	81
Colter	1908	0	19	3,300	High	6
City	1902	111	47	2,350	High	1
Golden Eagle Park (No. 4)	1973	0	20	37,141	High	7
Lone Pine	1936	0	98	15,000	Low	183
Daggs	1919	4,800	57	4,800	High	96
Parker Canyon	1962	3,710	80	1,266	High	9
Lower Lake Mary	1907	11,029	33	3,298	High	27
Upper Lake Mary	1941	16,576	38	11,000	Significant	54
Willow Creek	1936	5,980	65	8,100	High	25
Granite Creek	1920	4,598	81	616	High	45
Cc Cragin	1964	15,000	170	7,500	High	71
Jaques	1953	6,000	65	10,000	High	65
Lakeside	1904	1,120	21	16,200	Significant	9
Kennedy Park	1973	90	18	261	High	0
Florence Retarding	1965	0	21	2,300	High	70
Pena Blanca	1958	975	60	7,000	High	14
Lake Patagonia	1968	7,540	82	·	High	235
Luna	1911	1,390	27	·	Significant	36
Santa Fe	1892	215	42	700	High	5
Concho Springs	1927	1,198	24	625	Significant	7
Lee Valley	1899	420	20	600	Significant	3
Mexican Hay Lake	1908	0	11	25	Low	7
Nutrioso	1929	145	10	36	Low	11
West Cataract Creek	1947	415	36	4,920	Significant	6
Dogtown	1934	965	32	5,360	Significant	6
Kinnikinick	1956	2,532	13	600	Low	12
Knoll	1963	1,550	58	875	Low	4
Black Canyon	1964	1,581	60	1,000	High	6
Woods Canyon	1956	1,014	43	2,405	Low	10
Woodland	1914	90	18	2,014	High	5
Coconino	1954	255	30	2,860	Low	12
Chevelon Canyon	1966	7,000	84	8,000	Low	88
Ashurst Lake	1954	3,924	12	2,860	Low	1
Rogers	1910	62	12	·	Low	6
Lynx Lake	1962	1,472	70	20,000	High	19
Kino Springs	1965	0	19	30	Low	0
Fool Hollow	1956	3,217	60	15,300	High	102
Rogers Reservoir	1894	0	24	280	Low	0
Lebanon Reservoir #1 (Upper)	1910	115	40	210	Significant	1
Haralson	1919	68	29	430	High	0
Scott	1945	1,225	38	·	Significant	39
Clear Creek #1	1929	350	7	·	Low	607
Millett Swale	1958	0	24	6,120	High	40
Big Lake	1964	9,300	24	·	Significant	2
Continental #1	1972	71	32	58	High	0
Continental #2	1974	611	36	270	High	1
Central Detention	1948	0	22	2,100	High	6
Graveyard Wash	1962	0	26	9,000	High	19
Stockton Wash Retarding	1964	0	33	17,250	High	153
Frye Creek Retarding	1962	0	31	14,500	High	26
Frye Mesa	1929	135	91	815	High	4
Judia Foote Detention Dam	1957	159	29	9,300	Significant	5
Cluff Ranch #3	1956	140	30	800	High	1
Freeman Wash Retarding	1963	0	22	6,000	High	5
Fountain Lake	1970	310	31	2,500	High	1
Hesperus Wash (No. 36)	1973	0	36	11,800	High	3
Aspen (No. 6)	1973	0	30	15,830	High	2
Stoneridge (No. 19)	1973	0	25	6,950	High	1
Sunridge Canyon (No. 7)	1972	0	44	10,950	High	2
Short Creek Southside #2	1970	84	35	513	Significant	0
Leach Flood #1	1965	135	36	410	High	2
Powerline	1967	0	32	25,000	High	62
Magma Retarding	1964	0	21	1,000	High	62
Vineyard Road	1967	0	16	·	High	50
Rittenhouse	1969	4,060	17	18,200	High	92
Willow Springs	1970	3,654	80	3,055	Low	4
Tremaine Reservoir	1952	5,500	30	7,647	Low	17
Riggs Flat	1951	123	45	400	Low	1
Roper Lake	1961	313	17	100	High	0
Lake Of The Woods	1934	83	10	·	Low	16
Kaibab	1934	890	36	4,380	Low	18
Steel Dam	1898	10	46	102	Low	26
Masonry #2	1911	247	48	·	High	30
Tyler Reservoir	1929	375	9	·	Low	4
Canyon	1886	65	17	494	Low	0
Jarvis	1886	136	7	·	Low	·
White Mountain	1929	2,391	16	220	Low	6
Norton	1929	566	10	60	Low	3
Hog Wallow	1908	0	7	87	Low	4
Pool Corral	1908	0	12	·	Low	6
Ellis Wiltbank	1929	205	12	·	Low	4
Morton	1943	285	12	608	Low	1
Gillespie	1921	0	21	130,000	Significant	4,965
White Tanks #3	1956	0	26	24,000	High	24
White Tanks #4	1956	0	14	·	High	14
West Park	1974	0	25	4,980	High	1
East Park	1974	0	26	1,650	High	0
Camp Dyer Diversion	1926	690	45	·	Low	1,500
Oro Blanco	1950	67	18	·	Low	4
Lynx Creek	1927	21	52	·	Low	34
Mesa Reservoir	1935	111	35	·	Low	0
Hassayampa Check	1936	43	40	1,190	Low	2
Billingsley #2	1946	244	22	·	Low	3
Billingsley #3	1954	350	23	·	Low	3
Billingsley #4	1957	103	10	1,650	Low	7
Bunch Reservoir	1929	512	22	·	Low	1
Eagar-Slade	1945	522	18	736	Low	3
Crescent Lake	1934	5,800	22	·	Low	2
Glen Coe (Mckay)	1929	245	14	4	Low	0
Bear Canyon	1929	1,430	50	445	Low	2
Arivaca	1970	1,037	30	3,954	Significant	14
Lower Rose Canyon	1958	117	41	728	Low	1
Railroad Embankment	1929	840	27	2,980	Low	130
Fort Rock Ranch	1963	92	20	·	Low	31
Mclellan	1907	76	21	·	Low	8
Fredonia	1973	0	23	14,750	High	8
Boynton Lake Dam	1974	98	27	3,045	Low	10
Joshua Crosby	1944	52	14	·	Low	0
Buckeye Frs #1	1974	0	26	39,000	High	74
Canyon Mouth	1916	400	22	·	Low	200
Upper Goldwater	1932	525	52	8,334	High	3
Sheep Springs #1	1956	393	30	·	Low	3
Coronado Gen. Station	1978	4,650	53	450	Significant	3
Odell	1978	202	14	·	High	20
Riggs Reservoir	1929	39	31	30	Significant	0
Grant Morris	1975	0	44	·	High	0
Howard	1975	0	45	·	High	0
Chesley-Wamslee	1975	0	42	·	High	8
Foote Wash	1977	0	47	21,970	High	10
No Name Wash	1977	0	22	1,296	High	1
Lee	1981	0	61	·	High	0
Indian Farms	1981	0	45	·	High	0
Billingsley Dam	·	0	·	·	High	·
North Heights (No. 11)	1976	0	34	18,750	High	2
Guadalupe	1975	0	27	12,220	High	2
Buckeye Frs #2	1975	0	16	1,800	High	6
Buckeye Frs #3	1975	0	21	3,000	High	9
North Mountain Flood Detention #3	1975	0	26	4,120	High	1
Sunnycove	1975	0	40	8,250	High	1
Sunset	1977	0	20	4,100	High	1
Spook Hill	1979	0	15	21,000	High	16
Phoenix Detention Basin #7	1978	0	23	5,600	High	1
Short Creek Southside #1	1975	60	33	45	High	10
Cholla Bottom Ash Pond	1978	2,190	73	·	High	0
Cholla Fly Ash Pond	1978	15,400	80	·	High	2
Cholla Cooling Pond	1961	2,200	13	·	Significant	·
Trophy Lake	1975	105	33	·	Significant	2
Clear Creek #2	1986	498	12	80,000	Low	600
Atchison	1920	205	8	·	Low	3
Glen Livet	1929	110	12	120	Low	3
Udall	1910	0	24	500	Low	2,300
Coronado Gen. Station Reservoirs A	1984	206	12	·	Low	·
Ortega Lake Retention	1987	530	19	·	Low	34
Navajo Evap Pond 60-2	1980	280	50	·	Low	71
Gold Gulch #2	1982	0	99	4,477	Significant	·
Asarco 82	1983	0	48	·	Significant	0
Lower Chase Creek	1987	0	64	14,500	High	1
Palo Verde Evaporation Pond #2	1987	5,900	36	·	High	0
Saddleback Frs	1982	0	21	·	High	22
Harquahala Frs	1982	0	38	·	High	102
Palo Verde Evaporation Pond #1	1981	5,421	30	·	High	0
New River	1985	0	73	29,850	High	164
Adobe	1982	0	65	12,000	High	90
Thunderbird Park Reservoir	1985	37	44	75	High	0
Signal Butte Frs	1988	0	22	2,450	High	106
Schoens	1988	6,000	118	55,000	High	199
Jacques Marsh	1988	210	9	·	Significant	·
Green Valley Wwtp	1981	159	12	·	Low	0
Clearwell Reservoir	1992	178	77	·	High	0
Apache Junction Frs	1988	0	22	1,875	High	6
Boulder Flood Basin	1983	0	45	1,140	Low	1
Jumbo	1945	114	32	·	Low	88
Little Hell's Canyon	1951	65	30	8,000	High	54
Mexican Tank	1930	61	27	·	Low	5
Murphy Reservoir	1987	51	60	47	High	19
Walnut Canyon	1881	0	41	·	High	126
Stockton Hill	1997	69	27	2,910	Low	3
Number 10 Tank	1939	96	21	7,164	Low	7
Aspc-Safford Effluent Pond	1992	46	40	·	Low	·
Apache Station Ash/Scrubber Wdf	1995	2,910	30	·	High	0
Green Valley Park	1995	138	9	9,000	High	3
Gold Gulch 1a	1995	110	102	·	Significant	0
Slack	1995	42	50	·	Low	0
Mineral Park Flood Control Basin	1995	0	43	·	Low	0
Casandro Wash	1996	0	41	·	High	3
Mill Pond	1996	2,200	30	1,140	Low	4
Sedona Effluent Reservoirs	1995	0	8	·	Low	0
Main Pls	2008	0	106	·	Significant	0
Inlet Control Structure	2008	154	77	·	Significant	1
Rio Salado Town Lake	1997	2,419	15	215,000	Significant	13,000
Oro Ranch (Lake Mary)	·	0	31	·	Low	9
Page Effluent Ponds 2a & 2b	1998	204	19	2,000	Low	·
Kearny Lake	2000	150	28	1,405	High	0
Cook Reservoir	1940	0	18	·	High	1
Phoenix Cement Dam #1	1989	28	34	·	Low	·
28 Tank	1909	182	33	·	Low	·
Pace Tank Dam	·	135	14	·	Low	·
Little Reservoir	1921	1,128	13	·	Low	1
Brine Disposal Pond Dam	2001	193	19	625	Significant	0
Sweetwood (K4)	·	113	18	·	Low	·
Fenceline Tank	1944	180	17	·	Low	·
Dad Patterson	1944	199	15	·	Low	·
Paulden Tank #2	1961	0	11	·	Low	·
Del Rio #1 Dam	·	162	18	·	Low	·
Smith Tank	·	72	18	·	Low	·
Haumont Tank	·	225	28	·	Low	·
Broken Tank	·	124	21	·	Low	·
Patterson	1944	534	17	·	Low	·
Cortez Tank	·	114	15	·	Low	·
Twin Tanks	·	69	24	·	Low	·
The Lake	·	35	31	·	Low	·
Seligman	1954	0	15	·	Low	·
Tom Tank	·	84	14	·	Low	·
Nelson Tank	·	99	20	·	Low	·
Long Point Dam	·	946	15	·	Low	·
Town Of Eagar Wwtp	1983	66	7	·	Low	·
Avra Valley Wwtp	1994	437	14	·	Low	·
Gila Bend Wwtp	1995	55	12	·	Low	·
Sierra Vista Wwtp	·	636	16	·	Low	·
New Town #2	1945	40	45	·	Significant	·
H-V Reservoir	1883	260	15	·	Low	·
Red Lake Tank Dam	·	15	·	·	Low	·
Chino Valley North (Del Rio #3)	·	239	19	·	Low	·
Zonia Southwest Holding Tank	·	338	42	·	Low	·
Taylor Wwtp (Basins 1 & 2)	·	61	10	·	Low	·
Big Supai Tank	1882	56	34	·	Low	2
Owens Lake	·	164	20	·	Low	·
Scarlett Lake	1950	212	9	·	Low	·
Mallory Tank	1918	113	13	·	Low	·
Big Aso	·	95	16	·	Low	·
Swale Tank Dam	·	200	·	·	Low	·
Prescott Airport Wwtp	·	250	19	·	Low	·
Cottonwood (Oro Ranch)	·	132	22	·	Low	·
Sunnyside	1912	72	13	·	Low	6
Mesquite Generating Station Evaporation Ponds	2003	0	16	·	Low	·
Little Ortega Dam	·	120	12	·	Low	·
North Crescent Lake Dam	1934	5,700	17	·	Significant	2
Park Avenue Detention Basin Complex	2008	416	18	·	High	9
Red Mountain Freeway Levee	2008	0	16	·	High	·
Camp Verde Wwtp Duck Ponds	1982	189	13	·	Low	·
Palo Verde Evaporation Pond No. 3	·	0	45	·	High	·
Lower Chalk Tank	2002	54	22	·	Low	3
Upper Chalk Tank	2002	118	31	·	Low	3
Anderson	·	143	10	·	Low	·
Oneal Lake	1894	89	10	·	Low	·
Alpine Sanitary	1980	142	9	·	Significant	·
Unnamed Tank	·	53	11	·	Low	·
Maricopa Road Basin	1995	123	8	·	High	·
Green Road Basin	1995	254	11	·	High	·
Amarillo Valley Road	1995	0	8	·	Significant	·
White Road Basin	1995	262	8	·	Low	·
Gate Tank	·	132	23	·	Low	·
Crow Tank	·	63	39	·	Low	·
Plains Lpg Dam	1977	296	23	·	High	·
Painted Rock Dam	1960	0	181	401,700	High	50,800
Painted Rock Dam - Saddle Dike 1	1960	0	181	401,700	High	50,800
Mcmicken	1956	0	35	126,000	High	247
Whitlow Ranch Dam	1959	0	149	147,000	High	143
Whitlow Ranch Dam - Saddle Dike 1	1959	0	149	147,000	High	143
Morelos Diversion Dam	1950	0	11	140,000	Significant	·
Dreamy Draw	1973	0	42	5,900	High	1
Cave Buttes	1980	0	93	100,600	High	191
Tat Momolikot	1974	375,000	·	·	High	·
Foxboro Lake Dam	1905	16	13	243	Low	3
St. Marys	1925	124	7	·	Low	4
Soldier Annex Dam	1935	1,886	30	2,700	Low	3
Horsethief	1934	64	38	10	High	2
Granite Basin	1939	90	27	5,300	High	5
Sierra Blanca Dam	1958	196	11	300	Low	2
Hulsey Lake Dam	1950	39	30	810	High	2
Ganado	1994	2,812	·	·	High	·
Tsaile	1964	8,100	·	·	High	·
Many Farms	1943	18,000	·	·	High	·
Round Rock	1937	833	·	·	High	·
Wheatfields	1963	5,700	·	·	High	·
Glen Canyon	1963	27,000,000	710	276,000	High	108,355
Bartlett	1938	178,000	309	175,000	High	5,815
Davis Bor	1952	1,592,300	200	216,000	High	923
Horseshoe	1945	131,427	202	250,000	High	5,618
Horse Mesa	1926	245,048	305	·	High	210
Parker	1938	180,000	320	314,000	High	9,500
Mormon Flat	1924	57,852	224	·	High	120
Palo Verde Diversion	1958	5,000	46	75,000	Low	·
Laguna Diversion	1908	900	43	487,000	Low	287,000
Granite Reef Diversion	1907	250	29	165,000	Low	13,000
Theodore Roosevelt	1911	1,653,043	357	150,000	High	5,736
Stewart Mountain	1929	69,765	207	105,000	High	121
Round Mountain Detention Dam 1	1954	49	·	4,424	Low	19
Point Of Pines	1966	493	42	·	High	·
Dry Lake	1935	600	20	·	High	·
Tufa Stone	1944	406	·	·	High	·
Bootleg	1965	115	·	·	High	·
Cooley	1963	175	·	·	High	·
Davis	1956	5,700	·	·	High	·
Drift Fence	1963	130	·	·	High	·
Pacheta	1967	1,600	·	·	High	·
Horseshoe Cienega	1964	1,300	·	·	High	·
Reservation	1965	6,000	·	·	High	·
Christmas Tree	1965	575	·	·	High	·
A-1	1966	271	·	·	High	·
Shush Be Zahze	1966	160	·	·	High	·
Shush Be Tou	1966	180	·	·	High	·
Cyclone	1965	775	·	·	High	·
Sunrise	1967	15,600	·	·	High	·
Coolidge	1931	912,500	·	·	High	·
Headgate Rock	1941	7,025	·	·	High	·
Pasture Canyon	1930	230	·	·	High	·
Elgo	1979	6,000	·	·	High	·
Klagetoh	·	1,780	21	·	Undetermined	·
Nazlini	·	90	21	·	Undetermined	·
Trout Lake	·	60	33	·	Undetermined	·
Red Rock Valley	·	410	35	·	Undetermined	·
Canyon Diablo	1966	4,700	40	·	Low	·
Flat Rock Reservoir	·	174	25	·	Undetermined	·
Fluted Rock Lake	·	97	17	·	Undetermined	·
Upper Point Of Pines	1970	70	·	·	High	·
Blue Canyon	1984	1,900	·	·	High	·
Window Rock	1936	210	·	·	High	·
Menagers	1940	0	30	·	High	·
Antelope Detention Dam	1965	610	·	2,133	Low	26
Antelope Valley Detention Dam	1963	200	·	827	Low	5
Bob Crowder Detention Dam	1963	621	·	2,767	Low	48
Christman Detention Dam	1958	306	·	932	Low	12
Cove Detention Dam	1969	305	·	1,260	Low	8
Creighton Detention Dam	1956	2,970	·	15,400	Significant	·
Creosote Detention Dam	1981	205	·	466	Low	4
Crosby Tank Detention Dam	1959	1,100	·	2,200	Low	39
Flat Top Detention Dam	1962	0	·	392	Low	370
Grayhorse Detention Dam	1956	100	·	890	Low	·
Halfway Detention Dam	1940	0	·	·	Low	·
Hole-N-Wall Detention Dam	1960	880	·	840	Low	76
Hx Detention Dam	1956	1,660	·	3,578	Low	147
Iverson Detention Dam	1959	1,843	·	2,850	Low	84
Olga Detention Dam	1940	91	·	300	Low	2
Olney Draw Detention Dam	1953	180	·	2,810	Low	8
One Eleven Detention Dam	1968	449	·	1,488	Low	15
Oso Largo Dam	1971	120	·	5,442	Low	94
Reservoir Dike	1975	49	·	354	Low	1
Round Mountain Detention Dam 2	1954	650	·	5,250	Low	32
Ryan Detention Dam	1967	0	·	·	Low	·
San Simon Barrier Structure Detention Dam	1980	0	·	22,960	Low	2,192
San Simon Fan Drop Structure Detention Dam	1953	3,373	·	1,215	Low	·
Sands Draw Basin Detention Dam	1972	913	·	3,653	Low	43
Slick Rock Detention Dam	1981	1,022	·	3,604	Low	58
South Well Detention Dam	1981	168	·	250	Low	2
Upper Centennial Control Structure	1956	0	·	·	Low	·
West Doubtful Detention Dam	1968	799	·	2,967	Low	44
West Halfway Detention Dam	·	24	·	·	Low	4
West Well Control Dam	1966	0	·	5,220	Low	111
State Line Detention Dam	1952	207	·	4,104	Low	16
Ab-Bc	·	·	150	·	High	·
Number 4	·	·	40	·	High	·
Elders Gulch Tailings	·	·	·	·	Significant	·
Number 7	·	·	189	·	High	·
Alamo Dam	1968	0	283	41,500	High	4,770
Whitehorse Dam	1938	260	31	1,350	Low	3
Scholz Dam	1954	200	24	3,680	Low	51
J. D. Dam	1915	15	21	2,475	Low	6
Russell Tank Dam	1930	30	30	540	Low	2
Sycamore Dam	1939	1	47	290	Significant	13
Reach 11 Detention Dike 1	1977	19,500	35	·	High	34
Reach 11 Detention Dike 2	1977	14,600	40	·	High	32
Reach 11 Detention Dike 3	1977	14,600	35	·	High	24
Reach 11 Detention Dike 4	1977	11,400	40	·	High	21
New Waddell	1992	811,784	438	·	High	1,459
Railroad Tank Dam	1900	165	37	550	High	40
1 West	·	·	400	·	Low	·
2 West	·	·	125	·	Low	·
Silver Basin 1	·	·	225	·	Significant	·
3 West	·	·	307	·	Low	·
4 West	·	·	226	·	High	·
D Tailings	·	·	150	·	Significant	·
Mineral Park Tailings Dam	·	·	200	·	Significant	·
Sierrita	·	·	350	·	High	·
Lower Sabino Dam	1935	1	18	·	Significant	41
Soldier Lake Dam	1922	1	23	·	Significant	1

Reservoir FAQ

About Arizona dams & reservoirs

Where does the Arizona 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 Arizona 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 Arizona have so many dams?

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