HomeMy WebLinkAboutF-2. Azusa Water Supply Update Information Ite
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INFORMATION ITEM
TO: HONORABLE CHAIRPERSON AND MEMBERS OF THE AZUSA UTILITY
BOARD
FROM: GEORGE F. MORROW,DIRECTOR OF UTILITIES
DATE: APRIL 28, 2014
SUBJECT: AZUSA WATER SUPPLY UPDATE
On January 10, 2014, the Baldwin Park Key Well, a key indicator of the groundwater supply in
the Main San Gabriel Water Basin was at elevation 197.57. On April 22, 2014, the Key Well
elevation was 193.60, a decrease of 3.97 feet. The historic low at the Key Well was 189.2 feet on
December 3, 2009. The elevation of the Key Well has decreased due to the cessation of
Watermaster deliveries of imported water and a nearly total lack of rainfall since the end of
February. An additional delivery of imported water from USG-3 began on February 4, 2014 and
ended early on April 1. Most of the water delivered sank into the River bed north of Foothill
Avenue and is not making it to the Main Basin.
The Key Well needs a great deal of rain to recover. Although we have had rainfall, very little
has reached the Main Basin. As dry as everything is at this point, even an average daily rainfall
may not make it to the Basin. In a rainfall event that occurs when the ground of the watershed is
very dry, much of the actual rainfall is retained in the ground and does not run off until the
ground is saturated and the rainfall begins to run to the River. The observed effect of the rainfall
on the water behind the dams will be discussed more fully below.
The new water year began October 1, and rainfall to April, 2014 is 7.81 inches, measured at the
Pasadena powerhouse. This is 36% of average, up from last month's 33% of average. April's
rainfall so far is 0.24", 14% of an average April. Calendar year 2013 ending in December was
the driest in recorded history,but so far the 2013-2014 is still not the driest in history.
Upper San Gabriel Valley MWD's USG-3 turnout has not run in April. Currently, the North Pit
of the Canyon Basin is 28 feet below overflow and dropping at 1 foot per week; the South Pit is
51 feet below overflow and dropping 1.5 feet a week slightly impacted by very small amounts of
water being spread.
River inflow to San Gabriel Dam is 16.4 cfs. The Pasadena Conduit currently is not delivering
water from San Gabriel Reservoir to the Committee of Nine Canal.
UB-78
Water Supply Update
April 28,2014
Page 2
Currently, the Azusa Treatment Plant is delivering approximately 5.0 million gallons per day
(MGD) to the system. Current Azusa system demand is 17.32 MGD up 1.11 MGD from last
month, which is being met by the wells and the treatment plant; last month's demand was 16.21
MGD. Demand continues to move up instead of down as conservation measures would
anticipate. With the wells supplying over 12 MGD, coupled with Glendora's pumping demand
and Cal America's pumping demand on the Canyon Basin the Basin continues to be under stress
and dropping rapidly, without replenishment at this time.
On April 21, Morris Dam held 7,982.3, San Gabriel Dam held 8,520.1 AF, and behind Cogswell
Dam, very low at 1295.7 AF. On March 17, following the March 1 rain and subsequent runoff,
Morris Dam held 7,685.6 AF, San Gabriel Dam held 7,933.3 AF, and Cogswell held 1247.5 AF.
The reservoirs have gained water total gain in water held by the dams since March was 931.7
AF,not a significant increase.
The maximum capacity of all three reservoirs is 83,478 AF; the combined storage as of April 21,
2014 was 17,798.1 AF, 21.3% of capacity, including minimum pool, a slight increase from
March. Prior to the rains, the combined storage was 11,193 AF, 13.4% of capacity, including
minimum pool. Usable Committee of Nine storage remaining above minimum pool is
approximately 2,000 AF with the possibility of borrowing 3,000 AF more from the San Gabriel
Valley Protective Association. Committee of Nine storage is an important component of Azusa's
local water supply.
Statewide, water availability conditions continue to grow worse in some locations. However, the
State Water Project allocation has been raised to 5% from the initial allocation of 0%. More
Sierra snow and runoff is necessary to supply water to the State Water Project to gain a higher
allocation. Around the State, all reservoir levels are getting lower. Lake Mead is low and getting
lower and Lake Powell is normal for the time being. Metropolitan Water District seems to be
saying now that they don't have enough water to go around. Some cities in San Luis Obispo
County and elsewhere in the State are reaching the endpoint of their water supply.
Strict water conservation is necessary to reduce demand. Without more rain, a water supply
recovery will be all but impossible without imported water.
Prepared by: Chet F.Anderson P.E.,Assistant Director-Water Operations
UB-79