Lake Henshaw

Lake Henshaw is a reservoir in San Diego County, California, at the southeast base of Palomar Mountain, approximately 70 miles (110 km) northeast of San Diego and 100 miles (160 km) southeast of Los Angeles.^[1]

Lake Henshaw
Lake Henshaw from Mesa Grande Road
Lake Henshaw Show map of California Lake Henshaw Show map of the United States
Location	San Diego County, California
Coordinates	33°14′30″N 116°45′47″W
Type	Reservoir
Catchment area	217 square miles (560 km2)
Basin countries	United States
Managing agency	Vista Irrigation District
Surface area	1,140 acres (460 ha)
Water volume	55,000 acre-feet (68,000,000 m3)
Shore length1	5 miles (8.0 km)
Surface elevation	2,723 feet (830 m)
1 Shore length is not a well-defined measure.

The lake covers approximately 1,140 acres (460 ha) and holds 55,000 acre-feet (68,000,000 m³) of water when full (lowered in 1978 from its original capacity of 203,581 acre-feet (251,113,000 m³) out of earthquake concerns),^[2] in addition to groundwater stored in its local basin. It drains an area of 207 square miles (540 km²) at the source of the San Luis Rey River.

The lake was constructed in 1923 (102 years ago) (1923) with the building of Henshaw Dam, an earth dam 123 feet (37 m) tall and 650 feet (200 m) long. It is owned by the Vista Irrigation District and used primarily for agricultural irrigation.

The lake features opportunities for catfish and carp fishing. Boats and cabins are available for rental. It hosts The Carp Throwdown fly fishing tournament organized by the Fly Stop.

Climate

Climate data for Henshaw Dam (2723 feet above sea level)
Month	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Record high °F (°C)	90 (32)	93 (34)	101 (38)	109 (43)	116 (47)	121 (49)	122 (50)	120 (49)	120 (49)	112 (44)	98 (37)	95 (35)	122 (50)
Mean daily maximum °F (°C)	71 (22)	74 (23)	80 (27)	86 (30)	95 (35)	103 (39)	107 (42)	106 (41)	101 (38)	91 (33)	78 (26)	70 (21)	89 (31)
Daily mean °F (°C)	45.7 (7.6)	46.4 (8.0)	49.8 (9.9)	53.3 (11.8)	59.0 (15.0)	65.9 (18.8)	72.8 (22.7)	73.7 (23.2)	68.6 (20.3)	59.3 (15.2)	51.0 (10.6)	44.9 (7.2)	57.5 (14.2)
Mean daily minimum °F (°C)	29.7 (−1.3)	30.9 (−0.6)	33.9 (1.1)	36.4 (2.4)	41.6 (5.3)	45.6 (7.6)	52.5 (11.4)	53.0 (11.7)	47.5 (8.6)	38.9 (3.8)	32.4 (0.2)	28.7 (−1.8)	39.3 (4.0)
Record low °F (°C)	8 (−13)	12 (−11)	13 (−11)	21 (−6)	26 (−3)	29 (−2)	33 (1)	31 (−1)	26 (−3)	20 (−7)	11 (−12)	9 (−13)	8 (−13)
Average precipitation inches (mm)	5.40 (137)	5.61 (142)	4.41 (112)	1.59 (40)	0.65 (17)	0.10 (2.5)	0.18 (4.6)	0.35 (8.9)	0.41 (10)	0.98 (25)	1.87 (47)	3.72 (94)	25.27 (640)
Average snowfall inches (cm)	0.5 (1.3)	0.5 (1.3)	0.1 (0.25)	trace	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	trace	0.2 (0.51)	23.3 (59)
Source: NOAA[3]

See also

• List of dams and reservoirs in California
• List of lakes in California