CC 2016-03-22_09h Monthly Water Supply_Demand Update_Feb2016
MEMORANDUM
TO: CITY COUNCIL
FROM: GEOFF ENGLISH, DIRECTOR OF PUBLIC WORKS
BY: SHANE TAYLOR, UTILITIES MANAGER
SUBJECT: MONTHLY WATER SUPPLY AND DEMAND UPDATE
DATE: MARCH 22, 2016
RECOMMENDATION:
It is recommended the City Council receive and review the monthly Water Supply and
Demand Report.
IMPACT ON FINANCIAL AND PERSONNEL RESOURCES:
The cost to provide the report is limited to staff time, which equates to approximately
$500.
BACKGROUND:
The severe drought continues to impact the City’s water supply and demand. As a
result, the City Council declared a Stage 1 Water Shortage Emergency on May 26,
2015. This monthly update on the current supply and demand statistics will provide the
Council with the data required to make decisions related to Emergency Water Shortage
Restrictions and Regulations.
ANALYSIS OF ISSUES:
The severe drought continues. We have received 10.6” of rain since July 1, 2015 at the
Corporation Yard gauge. Lopez Lake is currently at 29% capacity (14,215 AF of
storage). The Low Reservoir Level Response Plan (LRRP) has been enacted.
At the Zone 3 Advisory Board meeting on May 21, 2015, the Board recommended that
the deliveries from the Water Treatment Plant be reduced by 10% starting April 1, 2015.
This is in advance of the Lake reaching 15,000 AF of storage, which is the automatic
reduction trigger.
In February the City’s water use was 33% below February 2013. The reduction
requirement imposed by the State Water Resources Control Board for Arroyo Grande is
28%.
Item 9.h. - Page 1
CITY COUNCIL
MONTHLY WATER SUPPLY AND DEMAND UPDATE
MARCH 22, 2016
PAGE 2
Based on current use and weather patterns, Lopez Lake, as predicted, reached the
15,000 AF storage level around November 1, 2015. The Lopez supply for water year
2015/16 for Arroyo Grande is 2,942 AF, which includes 883 AF of carry-over water.
Based on the projected water demand of 2,300 AF, we expect to be able to meet the
demand in water year 2015/16 with minimal groundwater pumping.
ADVANTAGES:
No advantages noted at this time.
DISADVANTAGES:
No disadvantages noted at this time.
ALTERNATIVES:
Not applicable at this time.
ENVIRONMENTAL REVIEW:
No environmental review is required for this item.
PUBLIC NOTIFICATION AND COMMENTS:
The Agenda was posted in front of City Hall on Thursday, March 17, 2016. The Agenda
and staff report were posted on the City’s website on Friday, March 18, 2016.
Attachments:
1. February 2016 Water Supply and Demand Charts
2. Lopez Reservoir Storage Projections
3. Zone 3 - Lopez Project - Monthly Operations Report
Item 9.h. - Page 2
City of Arroyo Grande Water Supply and Demand Update-January 2016 ATTACHMENT I
Rainfall
Cumulative Rainfall from July 1, 2015 to February 19, 2016: 10.6 inches
35 .0
30 .0
...,. 25.0 c = 20.0 ~ 15.0
~ 10.0
5 .0
0 .0
Cumulative Ra i nfall
·········· ... ...
JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN
•• •• •• Wettest Rainfall Year (1997-1998) ~Average Rainfall Year (1995-1996)
-• ·Driest Rainfall Year (2013 -2014) --2015 -2016 Ralnfall as of February 29, 2016
Note: Preci pitat io n data from AG Co rp Yard Stat io n No. 177.l from July 1966 -February 29, 2016.
Water Demand
To tal Ci1Y. Demand (AF /
Feb ruary 2013 179.7
Febr uary 2016 119.8
% Difference from 2013 -33%
WY 2013/14 YTD 2,934.3
WY 2015/16 YTD 1,919.5
% Difference from WY 2013/14 -35%
Predicted Supply and Demand
WY 2015 /16 Pr edicted Su p ply and Dem and
S,000
160
4.000
!.1,323 ~
3.000
:.\'
2.000 881
1.000 2.061
. 2,300 '
a Lopez Entitlement (-10%) rzJ Lopez Surplus C SMGB Groundwater Allocation
IJ Pismo Formatio n Groundwater rg WY 201 5/16 Target Demand
Note : The Water Year (WY) for water demand is from April to March.
Water Supply
Lopez Loke
I Remaining Allocated
Feb-16 WY 15Ll6 Year to Date ~
Lake Elevation (full at 522 .37 ft) 466.89
Storage (full at 49,200 AF) 14 ,37S.4
Storage -Percent Full 29%
Status En act ed
Current Entit lement Re d uction 10%
Deliveries (AF) 111.77 1,843.21 I 1,098.88
Note : The Water Year (WY) for Lopez Lake Is from April to March. The actual amount of storage in Lopez at the end of February 2016 was 14,215 AF ;
however, the storage amount and sto rage percentage above were adjusted to acc ount for the -160.4 AF of stored St ate Water Project wate r In the lake .
Groundwater
Feb-16 Calendar Year to Date Remaining En titlement
SMGB Production (AF) 8 .0
Pismo Formation Production (AF) 0 .0
City SMGB average well levels for February 2016 were the same as levels in February 2015 .
Note: Groundwater entitlement and production data is ba sed on the calendar year.
350
300
~250 ~
~
--..,
.... -....... , ... ... ... ... '
Water Supply, Demand and Delivery Chart
,--, ,
' ,,,. -'
..... --.... , ... ... ... ...
' '
9 .3
0 .0 NA
' ~2 00 ' .. , ' ..... , ,. ... _
_,, .... al
_ ___ .,,.
"' u ~ 150
·c
.~ 100
Oi
0 so
0
I ...
1: :-..
"" "" "" "" "" "" "" "" "" "' "' .-< '";< .-< '";< .-< .-< i .-< '";< .-< .-<
<5. > c ~ Oo a. > u c J:,
"' ~ :J QJ 0 QJ ~ .Cf <{ ~ <{ Vl 0 z 0
=Lopez Water Available (AF)
~ Lopez Water Deli very
-SMGB Water Pumped (AF)
-Predicted Pismo Formation Production
---Average Demand 20 11-2013 (AF)
~ I> "" t-
I 1:
"' "' "' "' "' "' "' "' "' "' <D <D <D .-< .-< '";< '";< '";< .-< .-< .-< .-< '";< .-< .-< .-<
.!. .!. > c :; Oo a. B > u c J:, .!.
"' a. "' ~ :J QJ 0 QJ ~ QJ "' ~ <{ ~ <{ Vl 0 z 0 u. ~
Bm Groundwater Allotment Available
-Pismo Formation Water Pumped jAF)
~ Predicted Lopez Water Delivery
lIIIIIID Predic ted SMGB Production
1,313.7
6,000
5,ooo_
~
4,000~
·;:
3,000 ·~
QJ a:
2,000-E:
c.
1000~
0
Note: Thes e production forecasts contain preliminary est imates of water production and draft predictio ns of future productio n based on historical
averag es .
Updated : 3/10/2016
Item 9.h. - Page 3
ATTACHMENT 2
rL
~
25,000
22 ,500
20,000
& 17,500
al ..
£
"'
Lo pez Rese rvoir Sto rage Proj ections
(preci p itation scenario source: www.LongRangeWeather.com)
Past 3 Year Avg _ Proj ection (AF)
-1991 Projection (AF)
••••• 15,000AF
-Actual Storage (AF)
Projected Storage (AF)
Precipitation Projection (i n)
Actual Precipitation (in)
8.70
Revised : 2129/20 16
('.., ~ ...
I '• .... ..,,
', I ',..,,
15.000 •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
I -... . ............•.......................... :...,. . . ........... w ... :
1"'-215 2.94 ' I ', ' .... f!, . --' ... ,_,
14,203 ....
' 1_117 1,74 12,500 ' '
-~ 0.89
0.35
10,000 8.08 uo
' I 0.96 ' 0 .74 ' o~ I ' 032 0
o.0&-003 -0.02 D .. "' "' "' "' "' "' "' "' "' "' "' "' co Cl) Cl) co Cl) co co co <D co co
0 0 0 0 0 0 0 0 0 0 0 0 0 0
"' "' "' "' "' "' "' "' "' "' "' "' "' "'
0 0 0 0 0 0 0 0 0 0
"' "' "' "' "' "' "' "' "' "' ..: ..: ..: ..: ..: ..: ..: ..: ..: ..: ..: ..: ..: ..: ..: ..: ..: ----..: ..: ..: ..: --~ Iii _., lii ~ ~ c '3 ~ a. 8 ti ~ c .. ~ --, ~ • --, IL ::E ::E --, < z -,
_., lii Is. >-c '3 Cl a. 8 ~ 0 • ~ " ~ IL :IE < :IE -, --, < z
Notes:
• For "Dry Months" (May -O ctober). projected increases and/or decreases in storage estimated to minic 2013 conditions.
• For 'Wet Months" (Novemb er -April), projected storage dedines assume annual d ownstream release of 4,200 AFY and deliveries of 4 ,530 AFY.
• For 'Wet Months", projected storage Ina-eases based on historic trends from actual storm data for the period of 1211993 through 612011 .
• Storage projection for 'Wet Months" assume that unsaturated conditions exist Increases in storage delayed un tl March due to drought conditions delaying reservo ir increase.
• Monthly rai nfall projections assumed to occur dl#ing the first week of each month.
•Rainfall projection provided by-.LongRangeWeather.com , and updated 10/3112015. Evaporation included in storage projection.
• 1991 Projection uses actual monthly storage changes, shown on 1st of month. 1991had26.33" of ra in , 13.98" in March. 1989 and 1990 had 9 .90" & 9 .99" of ra in respectively.
• Past 3 Year Avg . Projection uses historic daily capacity changes averaged from 2012 , 2013, 2014
G :\utilities\Zone 3\Advisory Commlttee\Reservoir Chart Info
10 .0
9 .0
8.0
7.0
6 .0 ~
c
5.0 0
;:l s ·a.
'(j
4 .0 Cl) ,_
D..
~ .c 3.0 ... c
0
~
2.0
1.0
0.0
Item 9.h. - Page 4
Item 9.h. - Page 5
THIS PAGE INTENTIONALLY LEFT BLANK
Item 9.h. - Page 6