verification of the 12-hour run program a report on the

Imperial Irrigation District

Metropolitan Water Districtof Southern California

Water Conservation Agreement

VERIFICATION OF THE 12-HOUR RUN PROGRAM

A Report on theSpecial Meeting of the Water Conservation Advisory Board

Presented byConservation Verification Consultants

onJune 19,1997

Conservation Verification Consultants

September 1997

TABLE OF CONTENTS

PART I -- CHARACTERIZATION OF 12-HD PROGRAM ............................ 1

PART II -- VERIFICATION STRATEGY AND OUTCOME ........................... 3

ON-FARM SAVINGS .................................................... 3

INCREASED LATEIL4.L SPILLAGE RESULTING FROM 12-HD’s .............. 6

NET 12- HD CONSERVATION SAVINGS ESTIMATES ANDDISCUSSION .......................................................... 8

EXHIBITS

Exhibit 1 -

Exhibit 2 -

Exhibit 3 -

Exhibit 4 -

Exhibit 5 -

Exhibit 6 -

Exhibit 7 -

Exhibit 8 -

Exhibit 9 -

Exhibit 10-

Exhibit 11 -

Exhibit 12 -

Exhibit 13 -

Exhibit 14-

Exhibit 15 -

Exhibit 16 -

Exhibit 17 -

12-Hour-Delivery Use By Calendar Year (1990-1996)

12-Hour Delivery Use By Month (1995)

12-Hour Delivery Use By Order Size (1995)

12-Hour Delivery Duration (1995)

12-Hour Delivery Use By Crop Group (1995)

12-Hour Delivery Use By Method/Purp0se (1995)

Average Field Size By 12-HD Irrigation Purpose (1993-1994)

IID Field Sizes For Single-Field Delivery Gates (1986-1995)

12-HD Data Collection Programs

12-Hour Delivery Program - Questionnaire For Every Tenth Order

12-HD Example 1: No Savings (No Buffer)

12-HD Example 2: Buffer Savings

12-HD Example 3: Minimum Workable Flow Rate

12-HD Example 4: Most Convenient Flow Rate

Average 12-HD Compared To 24-HD Replaced

Effective Utilization Of Excess 24-HD Water Reduces Potential Savings

Examples Of How Effective Utilization Reduces Potential On-Farm

Savings

CVC(mbk)File: mca>WCAB697.TOC i September 4, 1997

TABLE OF CONTENTS (cont.)

Exhibit 18 - Distribution Of On-Farm Reduction by Irrigation Method/Purpose (1995)

Exhibit 19 - 13 Laterals Included In Spillage Analysis

Exhibit 20 - Total Annual Spillage From 13 Laterals In Imperial Irrigation District

Exhibit 21 - Average Spillage By Operational Period From 13 Laterals In Imperial

Irrigation District

Exhibit 22 - History Of Spillage And Delivery Flexibility For 13 Laterals

Exhibit 23 - Operator Response Lag Time (Tr) Function

Exhibit 24 - 12-HD Program Savings Estimates (Rounded)

CVC(mbk)File: mca>WCAB697.TOC ii September 4, 1997

VERIFICATION OF THE 12-HOUR RUN PROGRAMA Report on the

Special Meeting of the Water Conservation Advisory BoardPresented by

Conservation Verification Consultantson

June 19, 1997

On June 19, 1997 the Water Conservation Advisory Board held a special meeting at the

Imperial Irrigation District’s Water Control Center. The Advisory Board asked the Conservation

Verification Consultants (CVC), Jack Keller, Grant Davids and Joseph Burns, to present their

verification strategy and findings related to the 12-Hour Run Program (Project 9) sponsored under

the IID/MWD Water Conservation Agreement.

This special meeting was chaired by Advisory Board Chairman John Veysey. It consisted of a

one-hour lbrmal presentation between 1:30 and 2:30 P.M. followed by 30 minutes of discussion.

This report contains copies of the overhead projector exhibits presented during the meeting,

discussion of the main points of the verbal presentation related to them and highlights of the

discussions that followed. The presentation was given in txvo parts. Part I, presented by Grant

Davids, characterized the historic use of 12-hour deliveries (l 2-HD’s), and Part II, presented by Jack

Keller, provided the strategies used and the outcomes of the CVC’s 12-HD verification activities.

PART I -- CHARACTERIZATION OF 12-HD PROGRAM

The discussion was opened by presenting and commenting on the following eight exhibits

which present statistics and data that characterize the historical use of 12-hour deliveries (12-HD’s)

in IID. These data were developed from IID’s AS400 data base (water delivery records) and

additional 12-HD details recorded by operational staff.

Exhibit 1

Exhibit 2

Exhibit 3

Exhibit 4

Exhibit 5

Exhibit 6

Exhibit 7

Exhibit 8

12-Hour-Delivery Use By Calendar Year (1990-1996)

- 12-Hour Delivery Use By Month (1995)- 12-Hour Delivery Use By Order Size (1995)- 12-Hour Delivery Duration (1995)

- 12-Hour Delivery Use By Crop Group (1995)

- 12-Hour Delivery Use By Method/Purpose (1995)- Average Field Size By 12-HD Irrigation Purpose (1993-1994)- IID Field Sizes For Single-Field Delivery Gates (1986-1995)

CVC(mbk)File: mca>WCAB697D.RPT 1 September 4, 1997

Exhibit 1 shows the total number of 12-HD’s used in IID by calendar year from 1990 through

1996. Davids pointed out that 12-HD use has risen steadily over this period, except in 1992, with the

largest jump in use occurring between 1993 and 1994.

Exhibit 2 shows the number of 12-HD’s used by month in calendar year 1995. Davids

pointed out that there are two distinct periods of high usage: one in the Spring associated with the

peak total water use period in liD and another in the Fall coincident with the heavy, use of sprinkler

irrigation for vegetable crop germination, cooling and irrigation.

Exhibit 3 shows the number of 12-HD’s used by order size in 1995. It was pointed put that

use in the "1.5 & 2" through "4.5 & 5" cfs order size tiers was more or less uniformly distributed,

with each tier representing between 13 and 16 percent of the total 1995 count. Use in the "6.5 & 7"

cfs tier was the largest, representing about 22 percent of the total, while use in the "0.5 & 1" and "5.5

& 6" cfs tiers was lowest at about 8 to 9 percent of the total.

Referring to Exhibit 4, Davids pointed out that as of 1995 the majority of 12-HD’s actually

had durations of about 12 hours. He also observed that, among remaining 12-HD’s, there was a

stronger tendency for durations to be shorter than 12 hours rather than longer.

Exhibit 5 sboxvs the use of 12-HD’s by crop group for 1995. Davids pointed out that the

vegetable and forage and silage groups accounted for nearly 80 percent of the total 12-HD use with

comparatively light use in the other crop groups.

Exhibit 6 shows 12-HD use by irrigation method/purpose for 1995. Davids noted that

heaviest 12-HD use was associated with germination, transplanting and cooling irrigations (which

are applied predominantly with sprinklers) and finish head irrigations. He also noted that these were

the types of uses originally targeted by the 12-HD Program, confirming that most 12-HD’s were

being used as originally intended. He noted that the CVC discovered liD growers had adapted

12-HD’s for small field irrigation and explained that small field irrigations using 12-HD’s are

equivalent to 12-HD finish heads used to complete irrigation of portions of larger fields.

Exhibit 7 shows the average field size by irrigation purpose for 12-HD’s used in 1993-94. Inresponse to a question, Davids clarified that field size was based on the number of acres actually

being irrigated with the 12-HD, not the total field size. He noted that average field size for finishhead irrigations was about 20 acres while the average field sizes for cooling, germination and

transplant irrigations ranged from about 34 to 40 acres. These values were contrasted to an average

field size of 71.5 acres in all oflID.


Exhibit 8 shows the distribution of all IID fields by size in 10-acre groups from 5 acres (+

acres) to 145 acres (± 5 acres). Bob McCullough, IID, suggested that an exhibit comparable

Exhibit 8 be prepared for the fields used in developing Exhibit 7.

In closing this initial part of the presentation, Davids reiterated that the historical data showedthat 12-HD’s were in fact being used primarily to replace the types of 24-hour delivery uses that were

originally targeted by the 12-HD Program. These were targeted because of their tendency to have

larger waste compared to other types of irrigation events. Hence, it was reasonable to conclude thatthe potential existed t~br 12-HD’s to be saving water.

PART II -- VERIFICATION STRATEGY AND OUTCOME

ON-FARM SAVINGS

Keller explained the verification strategy used for estimating the reduction in farm deliveries

and the logic underlying it. The strategy requires developing a sample database. For each 12-HDevent in the database, the volume of water that would have been delivered was estimated assuming

12-HD’s were not available. Then the volume actually delivered for the 12-HD event was subtracted

from this estimated without-project volume. The next step was to allow for there having been some

effective utilization of any excess water that would have been delivered. The final step was to use the

information in the database to develop a computational procedure for estimating the conservation

savings for all 12-HD’s.

Keller said that the reason for using this "event" based .strategy is because there is no other

way of estimating what would have happened without the 12-HD Program to compare with what is

now happening with it in place. He explained that the CVC has tried to develop alternate

conservation estimating procedures based on comparing pre-project and current delivery records on a

gate by gate basis as well as on various accumulated bases with limited success.

It was explained that in carrying out the "event" based verification strategy there were three

12-HD data collection programs to obtain estimates of what would have been ordered for 24-hours in

place of each 12-hour order. These are: 1) "Water Clerk", in which the Water Clerks in each division

gave their estimate of what would have been ordered; 2) "12 Cooperating Growers", in which two

cooperating growers from each of IID’s six divisions were queried as to what they would have

ordered each time they placed an order in that division; and 3) "l-in-10 Random Sample", which is

explained in detail below. Important comparable aspects of these three programs are shown in

Exhibit 9, 12-HD Data Collection Programs.

CVC(mbk)File: mca>WCAB697DRPT 3 September 4, 1997

Keller pointed out that the strategy used tbr the 1-in-10 program was to interview the initiator

of every tenth 12-HD order in each division. This resulted in obtaining a random sample containingthe responses from 1,656 interviews. Assistant Division Superintendents supervised the data

collection and independently checked the validity of the interviews by discussing the responses with

a random sampling of the growers. The CVC reviewed the 1-in-10 responses periodically and

brought to the attention of the Assistant Superintendents certain patterns and types of responses that

needed additional attention.

Exhibit 10, 12-Hour Delivery Program - Questionnaire For Every Tenth Order, was

shown and questions 17 and 18, which are the key questions, were highlighted by Keller. He pointedout that random sampling techniques of this sort based on telephone interviews are extensively used

by pollsters to make predictions such as election outcomes with excellent reliability. He alsoinformed the group that the CVC conducted about 40 grower interviews to check on the answers

provided in the questionnaire and to better understand the growers responses to specific questions.

Keller presented and discussed five examples of typical grower responses to question 17:

If 12-hour deliveries were not available, what would you have ordered for 24hours: cfs."

The five examples presented are provided in Exhibits 11 through 15.

Exhibit 11 -

Exhibit 12 -

Exhibit 13 -

Exhibit 14 -

Exhibit 15

12-HD Example 1: No Savings (No Buffer)

12-HD Example 2: Buffer Savings12-HD Example 3: Minimum Workable Flow Rate12-HD Example 4: Most Convenient Flow Rate

- Average 12-HD Compared To 24-HD Replaced

The top portion of each of these exhibits shows a graph of the flow rate in cubic-feet per

second (cfs) that "would have been ordered" for 24 hours and the corresponding acre-foot (AF)

volume. The bottom portion shows the flow rate actually ordered for the 12-HD and the

corresponding volume. In each of the examples the "Potential Savings" is the difference between

these two volumes.

Exhibit 11 shows the case in which the volume of water delivered for the 12-hour run is

equal to the volume that the interviewee would have ordered if 12-HD’s were not available. It was

pointed out that this is because the "cfs" of the 12-HD order is exactly twice the flow rate that would

have been ordered for 24 hours. Thus the potential savings is zero.


In Example 2 depicted in Exhibit 12 both the 12-HD and the 24-hour duration order itreplaced have 0.5 cfs buffers. Keller pointed out that during the CVC’s interviews they found this to

be common practice when supplying pumps in order to reduce the possibility of a small decrease in

the delivery resulting in the pump losing its prime. Thus the 12-HD is 0.5 cfs less than twice the flow

rate that would have been ordered for 24 hours and the potential savings is 0.5 AF.

Exhibit 13 demonstrates the case where the minimum workable flo~v rate for a regular 24-

hour duration order is greater than half the desired flow rate of the 12-HD that replaces it. As an

example of such a situation it was pointed out that the minimum practical flow rate for a finish head

needed to complete the irrigation of a flat crop is dependent on the width and length of the lands

(borders). Thus, for the example given, even though 2 cfs for 24 hours would provide the necessary

volume of water, 3 cfs had been needed to effectively irrigate the field so the potential savings is 2.0

AF.

Example 4, depicted in Exhibit 14, shows the case when the 12-HD order and the 24-hour

duration order it replaces are the same. This is done either because 4 cfs is the minimum practicalflow (like 3 cfs is in Exhibit 13) or 4 cfs is a most convenient flow" rate. Thus the potential savings

4.0 AF. IID xvater user J.C. Reeves challenged this as a viable option and said it was not logical that

anyone would do this because it would be too wasteful. Keller pointed out that during the CVC’s

field visits and interviews some growers and irrigation foremen said they did this prior to the 12-HD

Program, especially when they did not have time to work out the details more closely. Furthen’nore,

12-HD’s give them the flexibility to keep the water for 24 hours if necessary. Later, another IID

water user cont]nned this and said that occasionally he had ordered the same flow rate for a 24-hour

duration order prior to the availability of 12-HD’s.

Exhibit 15 shows the estimated average volume of water that the interviewees indicated

would have been ordered if 12-HD’s were not available, 6.6 AF, and the average volume actually

delivered, 4.2 AF, for all 1,656 12-HD events in the 1-in-10 Grower Database. These simple

averages are made up of all sizes of orders and the difference between them gives an average

potential savings of 2.4 AF per 12-HD. Little or no potential savings was realized from

approximately 46% of the 12-HD’s in the database because they were like Examples 1 and 2

presented in Exhibits 11 and 12. Approximately 8% were like Example 3 presented in Exhibit 13 for

the minimum workable flow rate and the remaining 46% were like Example 4 presented in Exhibit

14 for the most convenient flow rate.

Keller pointed out that the savings shown on Exhibits 11 through 15 are the potential

savings, i.e. the maximum amount of water that could be saved. In developing how much of the

potential savings was actually saved, he discussed the application of the grower responses to


question 18:

"18. Using this flow rate (referring to Question 17) for 24 hours, do you think you would

end up with too much water for this irrigation: No __ Yes

If yes, where would the excess water have gone (check one):

__Same field (SF) Directly to the drain (D)

__Another field, same gate (SG)

__Dift~rent gate (DG)

__Back to canal (gate would have been closed) (C)__Other (specie’):

The "Assumed Effective Utilization (%)" of the potential savings for the various possible responses

concerning the excess water and its destination was presented in Exhibit 16, Effective Utilization Of

Excess 24-HD Water Reduces Potential Savings.

Keller explained the method used by the CVC to analyze the growers’ responses to question

18 by giving an example of how effective utilization reduces potential on-farm savings. This was

done tbr Example 4 presented in Exhibit 14 for the "Most Convenient Flow Rate", as shown in

Exhibit 17, Example Of How Effective Utilization Reduces Potential On-Farm Savings. In theexample, the potential savings of 4.0 AF was reduced by 2.7 AF by applying an effective utilization

factor of 0.67 (for "back to the canal" responses where the flows would be intercepted) to the

potential savings. This results in reducing the net on-farm savings to 1.3 AF.

Keller explained how the CVC then took the results from the 1-in-10 Grower Database and

developed a mathematical procedure based on the irrigation method, 12-HD order size and crop

season to estimate the "Total Net Annual On-Farm Savings" for the 12-HD Program. The

percentages of the total on-farm reduction by irrigation method and purpose were presented in

Exhibit 18, Distribution Of On-Farm Reduction By Irrigation Method/Purpose (1995). He

noted that most 12-HD use is for the intended purposes of the program which was designed for

sprinkler irrigations and finish heads.

INCREASED LATERAL SPILLAGE RESULTING FROM 12-HD’s

Keller reported on the CVC’s effort to obtain good quality long-period spill records to

measure the impacts of 12-HD’s on IID spill. The CVC, with the assistance of IID Water Resource

Unit staff, reviewed records and inspected in the field 46 lateral spill sites to select records that met

the reliability, contributing area and period of record requirements and had good measurement


characteristics. Out of the 46 sites, 13 were selected that had records covering the 11 year period of

1986 through 1996. These laterals are listed in Exhibit 19, 13 Laterals Included In SpillageAnalysis.

The Stevens Recorder charts for the thirteen sites were digitized to develop an accurate spill

volume record. The total annual spillage for the 13 selected laterals for the 11 year period of 1986

through 1996 is presented in Exhibit 20, Total Annual Spillage From 13 Laterals In ImperialIrrigation District. Keller reported that the CVC compared the water delivered and annual spillage

for the 13 laterals with the remaining laterals in the IID system and found the 13 laterals to be

representative of the overall liD system.

The CVC divided the 11 years of lateral spill records into the following three operational

periods for the 12-HD lateral spill analysis: Pre-Program (1986 through 1990); Early-Program (1991

through 1993); and Present-Program (1994 through 1996). The average spillage for the 13 laterals

for each of the three periods is shown in Exhibit 21, Average Spillage By Operational Period

From 13 Laterals In Imperial Irrigation District.

The 12-HD program started after 1989 with slightly over 100 12-HD’s occurring along the 13

laterals in 1990. During the Early-Program period there were approximately 700 12-HD’s along the

13 laterals each year, and this has increased to approximately 1,000 12-HD’s per year during the

Present-Program period. The annual count or number of 12-HD’s and of liD’s 1996 additional

flexibility events (FxIID) and the average spill for the 13 laterals for the three Periods are shown

Exhibit 22, History, Of Spillage And Delivery Flexibilit3’ For 13 Laterals. Keller pointed out that

there was more spill associated with IID’s authorized additional flexibilityy events to better serve

growers during the Present-Program period than from 12-HD’s.

Keller pointed out that the CVC can only explain why there was a slight reduction in spillage

between the Pre- and Early-Program periods by noting the following: during the Early-Program

period for the most part all 12-HD’s were terminated after operating for the specified 12 hours; and

there were sufficient patrolmen available during the afternoon shifts to terminate the 12-HD’s in a

timely manner and also have time to readjust the lateral flows and deliveries to minimize spill. He

indicated that the reason lateral spillage has increased significantly during the Present-Program

period is because growers are now taking teller advantage of the additional flexibility IID offers by

having their 24-hour orders terminated early and their 12-HD’s terminated early or late, plus the fact

that there is a shortage of labor to handle this additional flexibility load. Furthermore, he mentioned

that the CVC is concerned about this increased spillage and is in the process of accompanying and

interviewing a cross section of zanjeros and swing and graveyard shift patrolmen in an effort to

better understand the current operational situation.


Keller introduced the concept of using a response lag time for assigning lateral spillage in

association with the endiag of 12-HD morning deliveries. The response lag time represents the

mismatch between when the flow reduction at the lateral heading reaches the farm delivery gate and

the gate is closed. In order to avoid delivery shortages, the delivery gate is usually closed before the

reduction in flow reaches it. The method used by the CVC to assign a response lag time to flexible

deliveries for a typical operational day is depicted in Exhibit 23, Operator Response Lag Time (Tr)

Function. It was pointed out that according to Exhibit 23 there would be no lag time during the

normal operational run period. However, the lag time would be 0.5 hours during the late morning

and afternoon when the afternoon patrolmen were on duty and it would increase to 1.5 hours during

the night hours. The amount of lateral spill associated with a given shut-off is equal to the deliveryflow rate times the response lag time.

NET 12-HD CONSERVATION SAVINGS ESTIMATES AND DISCUSSION

Keller described how the CVC subtracts the estimated spillage associated with 12-HD’s from

the net on-farnt savings to obtain the "Net 12-HD Program Savings". The results of the CVC

analysis of the net 12-HD savings estimates for 1994, 1995 and 1996 and the estimated net savings

for 1997 are presented in Exhibit 24, 12-HD Program Savings Estimates (Rounded). Keller

emphasized that the "i2-HD-Induced Spillage" in 1997 of 10,260 AF would be much higher without

the IID/MWD Automation Program: furthermore, the significant 12-HD savings would not have

been possible without the liD Water Control Center operations and system automation facilities now

in place.

Discussion between the CVC and growers in the audience followed the formal presentation.

Following are a few points that were covered during the discussion.

Larry Gilbert suggested that the 1-in-10 Grower Data Base was biased because the growers

were interested in retaining the 12-HD program and responded to the questionnaire to ensure

retention of the program. Keller reiterated that the 1-in-10 format assured a random selection of

growers and followed typical procedures and techniques used for polling purposes. Tb_e 1,656

responses was a large sample which assured that the results very likely ,,,,’ere not biased.

Several growers stated that there was so much operational flexibility currently permitted by

IID it was virtually impossible for the zanjeros and patrolmen to effectively make the necessary

changes required during certain shifts. Chairman Summers responded that the Water Conservation

Measurement Committee was aware that additional manpower is needed to effectively manage the

system and that this need is being addressed in the IID/MWD Program.


EXIIIBITS

Exhibit 112-Hour Delivery Use By Calendar Year

(1990-1996)28,000 ..............

24,000 .J ........................................

20,000 ’~

16,000

12,000

8,000

4,000

1990 1991Source: liD Water Deli~ Records

1992 1993Calendar Year

1994 1995 1996

CVC (I)E) ggd>c:\1002\p9_12hd\fannprsnt 1 8/26/97

Exhibit 212-Hour Delivery Use By Month

(1995)

3,000 ..............................................................................................................f

2,500

._>~ 2,000

¯ "r 1,500!

o 1,000

500

Jan Feb MarSource: lid Water Delivery Records

Apr May Jun Jul Aug Sep Oct

1995

Nov Dec

CVC (DE) ggd>c:\ 1002\p9_12hd\fannprsnt 2 8/26/97

25%

Exhibit 312-Hour Delivery Use By Order Size

(1995)

"r" 20%I

0L_

~ ]5%

~ ]0%

0%

0.5&1 1.5&2 2.5&3 3.5&4 4.5&5 5.5&6 6.5&7

Source: liD Water Delivery Records

CVC (I)E) ggd>c:\1002\p9_12hd\famlprsnt

Order Size (cfs)

8/26/97

6O%

Exhibit 412-Hour Delivery Duration

(1995)

50%

40%

30%

20%

10%

0%<4.5 5 6

Source: 1-in-10 Grower Database

7 8 9 10 11 12 13 14

12HD Duration (_. One Half Hour)

15 16 17 18 >18.5

CVC (DE) ggd>c:\lOO2\p9_12hd\.famaprsnt 4 8/26/97

Exhibit 512-Hour Delivery Use By Crop Group

(1995)50% .................................................................................................

40% ~.

30% ~

2O%

-1

10% --

O%

Source: liD Water Delivery Records Crop Group

CVC (DE) ggd>c:\1002\p9_12hd\lhnl~prsnt 5 8/26/97

~ 35%

’ 30%

"" 25%O

20%E= 15%

Z

"~ 10%OF- 5%O~-, 0%

Exhibit 612-Hour Delivery Use By Method/Purpose

(1995)


CVC (DE) ggd>c:\1002\p9_12hd\farrnprsnt 6 8/26/97

Source:

Exhibit 7Average Field Size By 12-HD Irrigation Purpose

(1993-1994)

Note: The average field size in liD is 71.5 acres. I

Cooling

1-in-10 Grower Database

Germination&

Transplanting

Other

Irrigation Purpose

Finish Head RegularIrrigation

CVC (DE) ggd>c:\1002\p9_12hd\fannprsnt 7 8/26/97

Exhibit 8liD Field Sizes For Single-Field Delivery Gates

(1986-1995)

20%

~ 18% -t ......./~ 16%

iT.o 14%_

" 12%Ez 10%

o 8%

o 6%

~ 4%

a.. 2%

O%5 15 25 35 45


55 65 75 85 95

Field Size(± Five Acres)105 115 125 135 >145

CVC (DE) ggd>c:\1002\p9_12hd\fanuprsnt 8 8/26/97

Exhibit 912-HD Data Collection Programs

PeriodWater Clerk

1989-93

12Cooperating

Growers1992-93

1-in-10RandomSample1993-94

Sampling Density 100% <5% Approx. 10%

No. of RecordsGenerated

Approx. 55,000 614 1,656

CVC (DF.) ggd>c:\1002\p9_12hd\fam~prsnt 9 8/26/97

Exhibit 1012-Hour Delivery Program - Questionnaire For Every Tenth Order

Serial Number(Water Resources)

Order Information - From Order Slip

1. Date of order: 5.Start date: Check One: AM PM

2. Account No.: 6. Order: cfs 10. Crop Code:

3. Time of order: 7. Canal: Gate: 11. Grower:

4 Division: 8. No. of days of delivery: 12.Phone Num:

Intervic~v Information

13. Name of interviexver:

14. Total area served by this gate: acres

15. Area to be irrigated with this order: acres

;~;~*;~"" OMIT ~S QUESTION cf~

19.Why are you using a 12-hour delivery (checkall that apply):

__ To improve irrigation performance (I)

Save water (S)

Convenience (C)

17.If 12-hour deliveries were not available, whatwould you have ordered for 24 hours: cfs

Note: Enter the head value in cfs, or check one of theappropriate spaces below if the grower says:

Save Labor (L)

__ Get better crop (B)

__ Save Money (M)

"half of the 12-hour order" H"same as the 12-hour order" S

__ Other (specify):

18.Using this flow rate for 24 hours, do you think youwould end up with too much water for thisirrigation: No Yes

If yes, where would the excess water have gone (checkone)."

20.Would a 24-hour irrigation have suited your needs(check one):

Yes No

__ Same field(SF) __.Directly to the drain(D) 21.Will this 12-hour delivery save you any water?

__ Another field, same gate(SG) Yes No Don’t Know

__ Different gate (DG) 22. Comments:

__ Back to canal (gate would have been closed) (C)

¯ Other (specify):

23 .Actual Delivery Date:

CVC (DE) bpt>c:\1002\p9_12hd\farmprsnt\grw_qst3.doc 8/26/97

24-HD ~

Exhibit 1 112-HD Example 1: No Savings (No Buffer)

1.5

1

O 0.5 ..

6 12 18

4.0 AF

Duration (hours)

12-HD

Duration (hours)12

Potential Savings

4.0 AF

0.0 AF

CVC (DE) ggd>c:\1002\p9_12hd\famaprsnt I 1 8/26/97

24-HD ~

Exhibit 1212-HD Example 2: Buffer Savings

2.50.5 cfs Buffer

2

1.51.

~_. 17.5 .

0 6 12 18 24

Duration (hours)

5.0 AF

12-HD

4.5

3.5

tO 2.5-

,’7 ~.5_1

0.5 cfs Buffer

6 12Duration (hours) Potential Savings

4.5 AF

0.5 AF

CVC (DE) ggd>c:\1002\p9_12hd\famaprsnt 12 8/26/97

12-HD Example 3:

24-HD ~"

Exhibit 13Minim um Workable Flow Rate

3

1

0.5!

6.0 AF

12 18 24

Duration (hours)

3.5

312-HD

~ :2.5

U.. 1

0.5 .[.

0

Duration (hours)12

Potential Savings

4.0 AF

2.0 AF

CVC (DE) ggd>c:\1002\p9_12hd\fam~prsnt 13 8/26/97

12-HD Example 4:4

Exhibit 14Most Convenient Flow Rate

24-HD ~ 3

0

Duration (hours)

18 24

8.0 AF

12-HD

4

Duration (hours) Potential Savings

4.0 AF

4.0 AF

CVC (DE) ggd>c:\1002\p9_12hd\farmprsnt 14 8/26/97

Exhibit 15Average 12-HD Compared To 24-HD Replaced

3.3

~ 2.524-HD ~

0.8

4.2

Duration (hours)18 24

6.6 AF

3.212-HD ~

"~" 2.1

0.0-,

0

Duration (hours)12

Potential Savings

4.2 AF

2.4 AF

CVC (DE) ggd c:\1002\p9 12hd,fannprsnt 15 8/26/97

Exhibit 16Effective Utilization Of Excess 24-HD Water Reduces Potential

SavingsResponse Regarding

Destination of Excess Water Assumed Effective Utilization (%)Drain 0

Same Field 10

Different Field 50

Canal--Intercepted 67

Canal -- Non-intercepted 12

No Excess 50


Exhibit 17Example Of How Effective Utilization Reduces Potential On-

Farm Savings

Example 4 -- Most Convenient Flow Rate

Potential SavingsEffective Utilization = 0.67 X 4

= 4.0 AF= 2.7 AF

Net On-farm Savings = 1.3 AF

CVC (DE) ggd>c:\lOO2\p9_l 2hd\farmprsnt 17 8/26/97

30%

Exhibit 18Distribution Of On-Farm Reduction By Irrigation

Method/Purpose (1995)

25%

20%

15%

10%

5%

0%

O "*-" IE3o OO

Source: 1-in-10 Grower Database

CVC (DE) ggd>c:\1002\pO_l 2hd\fim1~prsnt 18 8/26/97

Exhibit 1913 Laterals Included In Spillage Analysis

1. Elder 13 8. Orchid

2. Elder 9. R

3. Elm 10. S

4. Fillaree 11. Trifolium 5

5. Munyon 12. Trifolium 9

6. Myrtle 13. Vail 6

7. Olive

CVC (DE) ggd>c:\1002\p9_12hd\farmprsnt 19 8/26/97

14000

Exhibit 20Total Annual Spillage From 13 Laterals In

Imperial Irrigation District

12000

10000

8OOO

6000

4000

2OOO

0

Source: liD Spillage Monitoring Records Year


14000

Exhibit 21Average Spillage By Operational Period From

13 Laterals In Imperial Irrigation District

12000

10000

8000

6000

4O0O

2000

Source:

0

Pre-Program

(1986-90)liD Spillage Monitoring Records

Early-Program

(1991-93)

Operational Period

Present-Program

(1994-96)

CVC (DE) ggd>c:\ 1002\p9_12hd\fannprsnt 21 8/26/97

Exhibit 22History Of Spillage And Delivery Flexibility

For 13 Laterals1,200 .....................

,000 . .Aver~

~oo,

600 ~

o >

o

400

200

ge Pre-

14,000

13,000’ ! eroje!t Spill/! I , i 12,000

Project’Spill Average Early

|11,000

’ Spill

-i 10,000

, ~, -8,ooo..... ’- .............. - 7,ooo

01985 1986 1987

Source: lid Water Delivery and SpillageMonitoring Records

,15,oo0

i 4,000-[. 3,000

2,000

1,000

01994 1995 1996 19971988 1989 1990 1991 1992 1993

CFS File Year (July thru June)

CVC (DE) ggd>c:\1002\p9_12hd\farmprsn! 22 8/26/97

Exhibit 23Operator Response Lag Time (Tr) Function

1.50

1.25

1.00

0.75

0.50

~-} ~esponse LaglTimeL_..J Segmehts

o

0.25

0.00 [~0 2

(Typically8:00 am)

8 10 12 14 16 18 20 22 24

Time in Operational Day (hours)

CVC (DE) ggd>c:\1002\p9_12hd\fitrmprsnt 23 8/26/97

Exhibit 2412-HD Program Savings Estimates (Rounded)

Year

1994

Net On-farmSavings (AF)

26,570

12-HD-InducedSpillage (AF)

2,530

Net 12-HDSavings (AF)

24,040

1995 33,550 7,550 26,000

1996 42,060 14,990 27,070

1997 44,460 10,260 34,200

CVC (DE) ggd>c:\1002\p9_12hd\fam~prsnt 24 8/26/97

CONSERVATION VERIFICATION CONSULTANTS

TO: Bob M¢Cullougl~ID

COPIES: Tim O’Halloran/IIDElston Grubaugh/IID

FROM: Conservation Verification Consultants

DATE: September 3, 1997

SUBJECT: Response to Comment Provided During 12HD Presentation toWater Conservation Advisory Board

On June 19, the CVC made a presentation to the Water Conservation Advisory Board concerningverification of 12-hour delivery (12-HD) savings. As part of that presentation, we showed a figure thatillustrated the distribution of field sizes associated with all deliveries in IID (see attached Exhibit 8). Youcommented that a figure showing the distribution of field sizes associated with 12-HDs only would beuseful. The attached figures were developed in response to your suggestion and raise some interestingpoints regarding IID’s water delivery records. All figures are based on IID water delivery data that hasbeen provided for verification purposes.

Our understanding is that the "acre" field in the delivery records is supposed to represent the acresactually being irrigated with the water being delivered. To test this, we compared the "acre" data for 12-t lDs (11/I/95 through 10/31/96) with "irrigated acres" data collected for 12-HDs during the 1-in-10query program (10/1/93 through 9/30/94) (Figure 1). We expected the distribution patterns to be similarbut discovered that they are quite different. The "acre" data displays three modes around 35 acres, 75acres and >145 acres while the 1-in-10 "irrigated acres" data displays a single mode, skewed distributionaround 15 acres.

Next, we compared the "acre" data for the 12-HDs to the 1-in-10 "gate acres" data (Figure 2). Thisrevealed that the two data sets have very similar patterns. Figure 3 presents all three data sets to facilitatecomparisons among them.

We assume that the 1-in-l0 data properly captured the distinction between gate acres and irrigated acresbecause the farmers were specifically requested to provide this information. Therefore, it would appearthat the acres being reported by zanjeros and logged in IID’s delivery records are most representative oftotal field size and not irrigated acres.

Exhibit 8liD Field Sizes For Single-Field Delivery Gates

(1986-1995)

25%

¯ -~ 20%

OL

" 15%-~ ......~= ,

~ :o 10%

~ 5% ..........................

,’, !13% , ~

5 15 25Source: liD Water Delivery Records

35 45 55 65 75 85 95

Field Size (+ Five Acres)

105 115 125

..m.

135 >145

9/3/97 CVC DE bpt>c :\ 1002\frmrpsnt\irriacr.ppt

35.0%

Figure 112-HD Irrigated Acres

30.0%

25.0%

20.0%

15.0%

10.0%

5.0%

0.0%25 35 45 55 65 75 85

Field Size (+ Five Acres)

I=~Acre Column Delivery Detail Data (11/1/95 to I

[] ]~ 0/31/96)in 10 Irrigated Acres (10/1/93 to 9/30/94)

95 105 115 125 135 >145

DE bpt>c:\1002\frmrpsnt\Fieldsize12-HD.xls 9/3/97

30.0%

Figure 212-HD Gate Acres

25.0%

5.0%

0.0% 4-’5 15 25 35 45 55 65 75 85

Field Size(± Five Acres)

[]Acre Column Delivery Detail Data (11/1/95 to1 O/31/96)

[] 1 in 10 Gate Acres (10/1/93 to 9/30/94)

95 105 115 125 135 >145

DE bpt>c:\1002\frmrpsnt\Fieldsize 12-H D.xls 9/3/97

35.0%

Figure 3liD Field Sizes for 12-HD

30.0%

~ 25.0%.~_

.~ 20.0%

~ 15.0%

o. 10.0%

5.0%

0.0%5 15 25 35 45 55 65 75 85

Field Size(± Five Acres)

I~Acre Column Delivery Detail Data (11/1/95 to10/31/96)

r’11 in 10 Gate Acres (10/1/93 to 9/30/94)

[] 1 in 10 Irrigated Acres (10/1/94 to 9/30/94)

95 105 115 125 135 >145

DE bpt>c:\1002\frmrpsnt\Fieldsizel2-HD.xls 9/3/97


TO: Water Conservation Measurement Committee Members:Mr. Joseph Summers/Summers Engineering (Chairman)Mr. Kirk Dimmitt/MWDMr. Jesse Silva/IIDMr. Robert Krieger/Krieger & Stewart (CVWD)Mr. Gerald Davisson/PVID

COPIES: Mr. E!ston Grubaugb2IID Water ResourcesMr. Mike King/liD Project Management

FROM: Conservation Verification Consultants

DATE: August 15, 1997

SUBJECT: CVC Meeting with Water Conservation Advisory Board - June 19, 1997

On June 19, 1997 the Conservation Verification Consultants met with the Water Conservation Advisory Board at

the Imperial Irrigation District’s Water Control Center to discuss Verification of the 12-Hour Run Program. The

meeting was advertised in advance (see the attached Notice).

This special meeting was chaired by Advisory Board Chairman John Veysey. It consisted of a one-hour formal

presentation followed of by 30 minutes of discussion. The attached report contains copies of the visual exhibitspresented during the meeting, the main points of the verbal presentation related to them, and the discussions that

followed.


j seph I./Burns, ENG, PE

cc: Mr. Mike KingIID/Project Management

Water ConservationAdvisory Board

SPECIAL MEETING NOTICE

¯ John Pierre Menvielle ’.¯ D0ug Westmoreland.. , " "

.... Richard L~,erly

Iohn Veyscy, Chairm,’m

Don Emanuelli

J- C- Reeves., .....Jim Walker, vi~e Chairt/mn

Jim Abatti ’

John Grizzle ’Ralph Strahm " "

Secretary

Tim O;Halloran .

(619) 339-9265

"Verification of 12 Hour Run Program"&

"Water Conservation & Transfer Program"

ThursdayJune 19, 1997

1:30 P.M. - 3:00 P.M.3:30 P.M. - 5:30 P.M.

WATER CONTROL CENTER333 BAR.IONI BLVD.

IMPER_IAL

AGENDA

The Consultant Verification Committee (CVC) will make presentation on the ~nethodology used to calculate water savingsby the 12-hour mn program.

The ftrst part of the meeting will adjourn no later than 3:00 p.m.The WCAB will then reconvene at 3:30 p.m. (at the samelocation) to continue discussion of desired approaches that canbe used in a Water Conservation & Transfer Program. Thesemeetings are open to all interested parties mad will be presidedover by John Veysey.

verification of the 12-hour run program a report on the

Documents