1o. Water Supply System Analysis i4
CITY O 1 ).
CHANHASSEN
41 :
690 COULTER DRIVE • P.O. BOX 147 • CHANHASSEN, MINNESOTA 55317
(612) 937-1900 • FAX (612) 937-5739
f 1Y4/if
MEMORANDUM
TO: Don Ashworth, City Manager - 3 '`�
' FROM: Gary Warren, City Engineer
' DATE: October 3 , 1990 /Z' -•g -fu
SUBJ: Accept Proposal for Water Supply System Analysis
File No. PW113B
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As you are aware, we will soon be placing Well No. 5 into
' operation . Based on the recommendations made by Liesch &
Associates in their October, 1989 Water Supply Investigation
Report, this production well has been constructed in the glacial
' drift aquifer about 220 feet deep. The three existing production
wells in the City are bedrock wells which are approximately 600
feet deep. The net benefit to the City is that we have
successfully diversified our water supply system now between two
' separate aquifers and we also have identified a productive drift
aquifer which, in the case of Well No. 5 , yields 650 gallons per
minute and has potential for considerably more yield. The
' construction cost savings to the City for a drift well versus a
bedrock well is approximately $200 ,000 per well plus reduced
operations and maintenance costs due to the shallower pumping
depths.
As a part of the Well No. 5 design process, Liesch has done some
updating of the City' s current water useage. In order to
' properly evaluate the water demand experienced from the past five
years of rapid development and the addition of major water users
such as Rosemount Engineering and McGlynn Bakeries, and in order
' to provide meaningful information to the Comprehensive Plan and
MUSA line expansion efforts, it is necessary to expand this
process to include an update of the City' s 1985 Water System
Analysis Report. As you are aware, we are intending to add
' another well into the City 's system in 1991 and some design
decisions need to be made from sound analysis as to the
production capabilities of the new well and also longer range
' forecasts as far as adding water towers and other storage
facilities into the system.
I
Don Ashworth
11 October 3 , 1990
Page 2
I have therefore requested that B. A. Liesch & Associates prepare
the attached proposal to update the City ' s water system study
with regard to our current and future demands . At this point in
' time, it is not necessary to undertake a "Hardy-Cross" analysis
of the system as the 1985 information is still pertinent. These
project costs would be funded from the Water Expansion Fund
( 402 ) .
It is therefore recommended that the City accept the September
' 21 , 1990 proposal from Bruce A. Liesch Associates , Inc. for
preparation of a water supply system analysis report at an
estimated amount of $13 , 300 .
ktm
Attachment: September 21 , 1990 letter proposal .
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"_-*�( ''.' BRUCE A. LIESCH ASSOCIATES, INC .
• `` `""`` PryA HYDROGEOLOGISTS • ENGINEERS • ENVIRONMENTAL SCIENTISTS
13400 15th Avenue No •Plymouth,MN 55441•612-559-1423•FAX No:559-2202
September 21, 1990 '
Mr. Gary Warren, City Engineer
City of Chanhassen
690 Coulter Drive
Chanhassen, Minnesota 55317
Subject: Water Supply System Analysis ,
Dear Mr. Warren:
At your request, we have prepared a proposal to evaluate Chanhassen's Water Supply
System with regard to current and future conditions. We perceive the report to include:
- A review of past records to establish the base and peak flow volumes.
- Review population projections and growth patterns with the city planner. 1
- Contact high water use industries to establish past use patterns and future
projections.
- Project future water needs in five-year increments for twenty years. I
- Establish requirements for well capacity, storage and transmission for the
future. '
- Review existing facilities to determine immediate concerns.
- Recommend a comprehensive plan for system expansion including target
dates and estimated costs.
The estimated cost for completing this report is $13,300.00 as detailed on the attached
cost breakdown.
CITY OF CHANHASSEN
Hamm
SEP 26 1990
ENGINEERING DEPT.
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•
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Mr. Gary Warren
Page Two
September 20, 1990
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' Please note that we did not include a full Hardy-Cross analysis of the system in our
proposal. An analysis was performed in 1985. Many of the problems noted at that time
' with water main capacity have been corrected. Unless substantial residential development
has occurred or high use industrial water users have located in areas with marginal water
mains, the 1985 report should remain valid. If you are concerned with watermain capacity
' in certain areas, we have included an option for a Hardy-Cross Analysis for $4,300.00. We
have included in our cost an analysis of watermain capacity and new watermain
construction required for a new well near existing well number 2.
If you have any questions on this proposal, feel free to contact me.
Sincerely,
/Wilk)) 6,Lis.Ad1/4.-+
' ames Bullert, P.E.
JB/ke
Attachment
' kme:busprop920
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ESTIMATED COSTS
ENGINEERING SERVICES
WATER SUPPLY SYSTEM ANALYSIS
FOR
CHANHASSEN, MINNESOTA
Estimated
Task Cost
Review 1) ev ew Existing Records
Engineer 24 hours x $75.00 $1,800
2) Review Population Projections & Growth Patterns
Engineer 16 hours-x $75.00 $1,200
3) Review Industrial Water Use
Engineer 24 hours x $75.00 $1,800
4) Project Future Water Needs
Engineer 8 hours x $75.00 $600
5) Establish Design Criteria
Engineer 8 hours x $75.00 $600
6) Identify Inadequacies in Existing System
Engineer 16 hours x $75.00 $1,200
7) Recommend Water System Improvements for Design Period
Engineer 64 hours x $75.00 $4,800
8) Prepare Cost Estimates
Engineer 8 hours x $75.00 $600
9) Miscellaneous Costs
Clerical 8 hours x $24.00 $192
Direct Costs $500
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TOTAL ESTIMATED COST $13,292
USE $13,300
OPTIONAL SERVICES ,
1) Hardy Cross Analysis of Entire Watermain System
Jr. Engineer 60 hours $50.00 $3,000
Engineer 16 hours $75.00 $1,200
Clerical 4 hours $24.00 $ 96
$4,296
kme:busprop920