HomeMy WebLinkAbout07/17/1990, 5 - FEASIBILITY STUDY FOR CLOUD SEEDING (WEATHER AUGMENTATION) yp y AMI „camL%A�S OBISPO
I����41���llll�llll'��1�I II MEETING DATE:
City of Sa �
uWJul 17, 1990
i COUNCIL AGENDA REPORT ITEM NUMBEii:
From: William T. Hetland �� Prepared By: Steve R. Johnson
Utilities Director Water Distribution Supervisor
Subject: Feasibility Study for Cloud Seeding (Weather
Augmentation)
RECOMMENDATION:
By motion, authorize staff to negotiate and Mayor to execute an
agreement for a cloud seeding feasibility study, cost not to
exceed $27,400 with the firm of North American Weather
Consultants.
BACKGROUND:
The City of San Luis Obispo has experienced four consecutive
years of lower than normal rainfall which has resulted in lower
than normal reservoir storage levels. During this period, the
staff under direction of Council, has been investigating and
developing alternative water sources to augment the depleting
supply of surface water. The areas of investigation and
development include:
1. Groundwater Development Program - Phases I, II and III.
2. Feasibility Study - for Salinas Dam expansion.-
3 . Desalination Feasibility Study.
In addition to the aforementioned areas, the City Council has
instructed staff to investigate the possibility of augmenting the
City's water supply through "cloud seeding. "
-The firm of North American Weather Consultants has proposed to
investigate the feasibility of increasing water supplies for the
City through weather augmentation. North American Weather
Consultants has been in operation for forty years with recent
experience and expertise on the Central Coast.
Between 1968 to 1973, North American Weather Consultants
completed a weather augmentation feasibility study and pilot
program for Santa Barbara County. The Santa Barbara II Research
Program demonstrated that significant amounts of additional
precipitation could be generated by modifying portions of
naturally occurring winter storms. Santa Barbara has had an
ongoing weather augmentation program since 1977. This program
has resulted in a 15-20% increase in runoff.
Pacific Gas and Electric Company and other hydropower generating
agencies have used weather augmentation for years to increase the
snow pack in the Sierra Nevadas resulting in greater spring
runoff.
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COUNCIL AGENDA REPORT
Cloud Seeding
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Staff recommends not to solicit requests for proposals for this
study and sole source the project to North American Weather
Consultants for the following reasons:
1. Limited number of firms offering this type of service; NAWC.
is the sole provider in this area.
2. North American Weather Consultants have the expertise and
experience within our immediate region.
3. Prohibitive time frame in which to implement the weather
augmentation program, if the study indicates feasibility.
PROPOSED PROJECT:
The basic purpose of the feasibility study is to determine the
effectiveness of weather augmentation in the San Luis Obispo area
and the resulting impact on reservoir yields.
The proposed steps of the study are as follows:
1. Accumulate available monthly (November - April) rainfall'
records for the following NWS climatological stations: Paso
Robles FAA AP, Paso Robles, Pismo Beach, Cal Poly, Santa
Margarita Booster Station, and Salinas Dam.
2. Acquire any available runoff data for the reservoirs in San
Luis Obispo County (Lopez, Santa Margarita and Whale Rock) .
3 . Establish correlations between selected San luis Obispo
precipitation stations and runoff into the three reservoirs.
4 . Utilize the results of the Santa Barbara II Research Weather
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Modification Program (1968-1973) to estimate the amount of
additional precipitation produced through weather
modification stratified by type of storm.
5. Identify the storm types that affected San Luis Obispo
County during the November-April period from 1941-1980.
6. Apply the percentage increase derived from the Santa Barbara
Research Program for each storm type to each of the storms
from 1941-1980 for each of the San Luis Obispo County
precipitation gauges that are correlated to the runoff into
the three reservoirs.
7. Accumulate the natural and augmented precipitation amounts
for the precipitation gauges by month and by season
(November-April) .
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COUNCIL AGENDA REPORT
Cloud Seeding
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8. Utilize the correlations between precipitation and runoff to
estimate the augmented runoff into each of the reservoirs.
Accumulate the estimated augmented runoff on a seasonal
basis.
9. Estimate the cost of conducting a seasonal weather
modification program to affect the three reservoir
watersheds.
10. Acquire estimates of the value of water from the three
reservoirs.
ll. Calculate a preliminary benefit/cost ratio to assist the
water managers in assessing the feasibility of a program.
12. If a program appears feasible for one or more of the
watersheds, then a preliminary design of a weather
modification program would be prepared.
13. Identify environmental compliance and permit requirements
for the proposed program.
14. Prepare a final report and provide 20 copies to the City.
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The consultant can complete this analysis within 90 days so that
a program could be implemented this winter if necessary.
CONSEQUENCES OF NOT TAKING RECOMMENDED ACTION:
Loss of potential additional water resources, which would
negatively impact existing supplies if the next rainy season is
very low, as it was in 1989.
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FISCAL IMPACT:
The proposed study cost is $27,400. Since this is not a budgeted
program and no funds were specifically identified, staff
recommends budget carryover funds be utilized.
Use of carryover funds has no negative impact on 1990/91
operating budgets. Water Engineering/Administration carryover is
expected to be $40,000 and the overall Water Division carryover
will exceed $150,000. This is more than adequate to fund the
study and the program savings already identified in the Water
Rates report of June 12, 1990.
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COUNCIL AGENDA REPORT
cloud Seeding f
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ALTERNATIVES:
1. Do not proceed with study. This allows the $27 ,400 to be
used to fund the water fund deficit for 1990-91. This is
not recommended because there is an urgent need to identify
more sources of water.
2. Seek request for proposals from additional firms. This
alternative is not recommended as it would delay the study,
resulting in a potential loss of water source in the coming
rainy season.
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