HomeMy WebLinkAbout2000-12-20 Agenda Packet - Board (6) Agenda Item # 4
Memorandum
To: Board of Directors
From: Peter L. Holzmeister
Date: December 15, 2000
Preparation of analysis of groundwater basin safe yield
The Board has approved the concept of this District working with Placer County Water Agency
in planning and implementng regional water solutions. Placer County Water Agency is currently
working with Placer County Planning Department to update the Martis Valley General Plan. This
plan will determine the allowable development in the Martis Valley basin.
PCWA and TDPUD have been talking about revisiting the calculation of safe yield of the
groundwater basin. PCWA agrees that if the safe yield of the basin is recalculated, TDPUD
should be lead agency. I have asked Nimbus Engineers to provide us with a proposal to
conduct the review, a copy of which is attached. The total price is $70,000.
A cost sharing has been suggested as follows:
• TDPUD share is $10,000
• PCWA share is $10,000
• Northstar Community Services District share is $5,000
• Developers who are currently applying to Placer County for approval will together fund the
remaining $45,000.
If the TDPUD Board approves this project, TDPUD would be in control of the consultant. The
funding of the project would be as indicated above. The work product would be available to the
water purveyors, the various land use agencies, and the public at-large.
Our current evaluation of the basin safe yeild is dated. When John Sharpe prepared it in 1974
he suggested that it be reviewed as additional information becomes available. We now have
much more information. We also have increasing development activity in the basin and we have
the limitations in TROA looming. We need to perform this analysis.
Recommendation
I recommend that the Board approve the proposal submitted by Nimbus Engineers to perform
services in connection with calculation of safe yeild for the groundwater basin.
Nimaq bus Cn9inceRs
December 1, 2000
Mr. Ed Taylor
Water Superintendent
Truckee Donner Public Utility District
11570 Donner Pass Road
P.O. Box 309
Truckee, California 96160
RE: Scope of Services, Time Schedule, and Cost Estimate for Development of a Martis Valley
Surface/Ground Water Budget for Determination of a Ground Water Safe Yield
Projection.
Dear Mr. Taylor:
In response to the request made by Mr. Peter Holtzmeister on November 28, 2000,Nimbus
Engineers has prepared this proposal to provide a scope of services, time schedule, and cost
estimate for developing a Martis Valley surface/ground water budget. This budget will update
the work that was first undertaken and completed by Dr. John Sharp in 1975. It is anticipated
that the information generated from this study will define the amount of ground water that will be
available to TDPUD, Placer Counry,and to the various developers requesting ground water for
their proposed developments. As a result of our conversation regarding a time frame for
completing the study, it is anticipated that a draft of the study will be completed and submitted to
your office by the second week in February 2001. With this accelerated time frame, we can meet
the March deadline as required by Placer County. The following is a proposed Scope of
Services, a proposed schedule, and associated Cost Estimate.
Scope of Services
Task I Collection and evaluation of existing data
• The collection and evaluation of existing data will involve reviewing the original
Hvdro-Search, Inc. (John Sharp) report completed in 1975, then collecting and
reviewing all of the other basin reports and on going studies (from various research
agencies) dealing with surface and ground water that have been completed since then.
• Because of our recently completed report Ground Water Resource Evaluation,
,Nimbus Engineers, :November ?000, several contacts have already been established
with the different State of California agencies that will be resources to provide
additional data for the proposed study. It is anticipated that the Nevada County
3785 Baker Lane. 4201 • Reno. Nevada 39509 • (775)689-8630 • Fax (775)689-8614 • nimbus@ nimbuseneineers.com
Department of Health will be asked to provide additional data to be used for water
chemistry evaluation. This data wilt help provide an analysis of the surface
water/ground water interconnection.
• A collection and evaluation of the surface and borehole geophvsicat oroQrams that
have been completed will also play an important role in understanding the geologic
setting of the basin.
• The State of California. USGS. Corp of Engineers. and other agencies will be
contacted with regard to current and historical stream gauging activity and data
collection. It is not anticipated actual stream gauging will be required to supplement
the gaging activity and data that is currently being collected. The collection and
evaluation of this data will be important to develop an understanding of the recharge
and/or discharge effect of the Truckee and contributing streams.
Task II Develop surface/ground water budget
Development of the Mattis Valley surface/ground water budget will involve incorporating the
following information and data into basin wide understanding of how much surface and ground
water is safely available for use.
• Precipitation/runoff calculated values for every sub-basin area throughout the
Martis Valley hydrographic basin will be calculated. It is anticipated that by
using available soil coverage maps, soil conservation curve numbers can be
established for the individual soil types found in the basin. By using the soil
curve number, land gradient values, elevation, vegetation, and precipitation
intensity, the surface run-off can then be calculated. The surface run-off value
can be checked for some basins which have automatic stream gauging points.
• Development of geologic cross-sections at strategic locations in the valley to
determine alluvial/volcanic thicknesses and the bedrock basement location.
After determination of the thicknesses from the cross-sections, a determination
of the saturated thicknesses of the different aquifers can be calculated.
A determination of the recharge/discharge effects of the Truckee River and the
other surface streams and springs found within the basin will have to be made.
• All of the existing water usages within the basin will have to be calculated.
This will involve collecting and putting into the basin side study the ground
and surface water consumption for the different places of use including
commercial, agricultural, and municipal.
• Impacts of water chemistry on the safe yield on the basin. This area will be
evaluated because of the interaction being the relative good water found in the
alluvial material and the poor quality water that is generally found in the
volcanics.
Task III Preparation of report
The report will include all of the data and information that went into the develooment of the
surface ground water budget and will contain the rationale behind the calculations included. It is
anticipated that the information contained within the report can be the starting point for the
development of a basin-wide three dimensional ground water flow model.
That model will be used as a toot for determining overall basin water planning and management
of the ground water resource. Before proceeding with the three dimensional model the
surface/ground water budget must be established.
Task IV Presenting report to TDPUD and meetings
Under this task the report will be presented to the TDPUD in draft form the second week in
February, then after receiving comments, the report will be finalized and presented to the
TDPUD board on February 21. Time has been included for an additional two or three meetings
with different agencies, if required.
Cost Estimate
Task I Collection and evaluation of existing data
Senior Hydrogeologist/PM 80 hrs @ S92/hr $7,360
Hydrogeologist 160 hrs @ $65/hr 10.400
Subtotal S17,760
Task II Develop surface/ground water budget
Senior Hydrogeologist/PM 80 hrs @ $92/hr S7,360
Senior Hydrogeologist 40 hrs @ S85/hr 3,400
Hydrogeologist 160 hrs @ S65/hr 10,400
GIS/AutoCAD 40 hrs @ $45/hr 1.800
Subtotal S22,960
Task III Report preparation
Senior Review 16 hrs @ S125/hr S27000
Senior Hydrogeologist/PM 80 hrs @ S92/hr 7,360
Hydrogeologist 160 hrs @ $65/hr 10,400
GIS/AutoCAD 40 hrs @ S45/hr 1.800
Subtotal 321,560
Task IV Presenting report to TDPUD and meetings
Senior Hydrogeologist??[ 16 hrs @ S92/hr S 1.472
Subtotal 51,472
Total S63,752
Contingency 10% S6,373
Project Total S70,127
As shown on the included time schedule. Nimbus Engineers is prepared to commence work on
this project as soon as December 4. Given the tight time frame and the data and information that
has to be collected and evaluated. the sooner the work can star, the more detail that can �zo into
the project and the model.
If you have any questions regarding the Scope of Services. the Time Schedule. and Cost
Estimate,please contact me at (775) 689-8630.
Sincerely.
NIMBUS
//} /ENGINEERS
OaAA-c5
David Carlson
Senior Hydrogeologist/Project Manager
2000 2001
Act. Activity Orig Early Early Dec Jan Feb
ID Description Dur start Finish 1 6 15 22 29 5 12 19 26 2 9 16 29 26
10 Research/Data Gathering1-Dec-00 31-Dec-00 < '"` �"t' - >
20 Data Review 8-Dec-00 5-Jan-01 < � -->
3 Develop Budget M 31-Dec-00 31-Jan-01 <--=-------->
40 Report Preparation 19-Jan-01 18-Feb-01 <-------------------------------->
50 Report Submittal 21-Feb-01 21-Feb-01 'Feb 21
Ojad slap SCHEDULE _tl�%„
eject Finish 21-FBb.01 Me
Valley � \ Nimbus en�IneeRS
�11 0905 BGh6f L.,SW4 201 • ema.NV 09509
Surface/Groundwater Budget Mall:P.O.Box 10220 • Hera.NV 09510
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