A-3. Discussion of 10-year Water Supply Plan0
CITY OF
CHANHASSEN
7700 Market Boulevard
PO Box 147
Chanhassen, MN 55317
Administration
Phone: 952.227.1100
Fax: 952.227.1110
Building Inspections
Phone: 952.227.1180
Fax: 952.227.1190
Engineering
Phone: 952.227.1160
Fax: 952.227.1170
Finance
Phone: 952.227.1140
Fax: 952.227.1110
Park & Recreation
Phone: 952.227.1120
Fax: 952.227.1110
Recreation Center
2310 Coulter Boulevard
Phone: 952.227.1400
Fax: 952.227.1404
Planning &
Natural Resources
Phone: 952.227.1130
Fax: 952.227.1110
Public Works
7901 Park Place
Phone: 952.227.1300
Fax: 952.227.1310
Senior Center
Phone: 952.227.1125
Fax: 952.227.1110
Website
www.ci.chanhassen.mn.us
A-3
MEMORANDUM
TO: Todd Gerhardt, City Manager
FROM: Paul Oehme, Director of Public Works/City Engineer
DATE: June 13, 2016 ow
SUBJ: Discussion of 10 -year Water Supply Plan
BACKGROUND
Every 10 years public water suppliers serving more than 1,000 people, large private
water suppliers in designated Groundwater Management Areas, and all water
suppliers in the Twin Cities metropolitan area are required to prepare and submit a
water supply plan. In the past this supply plan was called the water emergency and
conservation plan.
The goal of the water supply plan is to help water suppliers implement long-term
water sustainability and conservation measures, and develop critical emergency
preparedness measures. Communities needs to know what measures will be
implemented in case of a water crisis.
This plan needs to be approved by the DNR before any additional water appropriation
will be allowed by the City. Also this plan will be incorporated into the
Comprehensive plan update.
The metro area has seen a significant increase in water use primarily from
groundwater and decrease in surface water use. With the increase in ground water
use aquifer levels have decreased.
Water use in Metro Area
350
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Chanhassen is a Community for Life - Providing for Today and Planning for Tomorrow
Todd Gerhardt
10 -Year Water Supply Plan
June 13, 2016
Page 2
Water Demand
Water demand in Chanhassen is mainly driven by summertime water use. The average
wintertime use is a little over 2 million gallons a day, but during the summertime it has been as
high as 9.8 million gallons a day in 2006. Summer water demand is highly variable and mainly
dependent on precipitation and temperature. Over 40% of the city's annual water production is
used in the summer months and primarily for outdoor use. Over the past six years summer
precipitation has been above average so the maximum day demand has been down. In 2016 the
maximum day demand was 6.2 million gallons.
As part of the water supply plan large volume users are monitored. Below is a list of the top 10
water users in Chanhassen:
Customer Use Category (Residential, Industrial, Commercial,
Institutional, Wholesale)
1
General Mills
2
Rosemount, Inc. (Emerson)
3
Lifetime Fitness
4
Banta Direct Marketing
5
I IWCO Direct
6
Chanhassen Dinner Theater
7
Kwik Trip (2)
8
ISD 112
9
City Of Shorewood (18 Homes)
10
Powers Ridge
Percent of
Amount Used Total Annual
(Gallons per Year) Water
Some of these users have implemented water conservation programs.
20,357,000
2.23%
16,963,000
1.86%
8,635,000
0.95%
6,253,000
0.69%
5,594,000
0.61%
5,429,000
0.60%
3,596,000
0.39%
3,542,000
0.39%
3,509,000
0.39%
3,320,000
0.36%
The city has also looked at water conservation measures. The Parks Department has recently
implemented a smart irrigation monitoring system for all irrigation areas. Staff is also evaluating
water reuse for city irrigation in some areas of the community.
The plan also projects out to 2040 with an estimated population served of 34,730. The projected
maximum day water demand is 15.6 million gallons.
Water Sources
The city has 14 municipal production wells. Most of these wells are over 500 feet deep and in
the Jordan aquifer. The city also has four municipal interconnects with other communities.
These 111Lb1 VV1111v"o Voll a,aoou in times of water emergencies. The interconnections are with
Chaska, Shorewood (2), and Eden Prairie.
The city monitors the well aquifer levels with the drawdown probes on a real time basis. The
city has seen aquifer levels drop over time which is consistent across the metro area. For
example, the static water level of Well #2 which was drilled in 1969 in the east well field has
Todd Gerhardt
10 -Year Water Supply Plan
June 13, 2016
Page 3
fallen 41 feet. Well #3 drilled in 1977 in the west well field has fallen 19 feet. The city has
seen a little rebound in the aquifer levels over the past five years with less high summer demand.
Natural Resource Impacts
The city's water supply plan has to take into account natural resources that could be impacted by
water production. The city has designated trout streams and the Seminary fen within the city
limits. Current and future municipal wells have been planned to be far enough away from these
natural features to minimize impacts. Monitoring wells have also been installed to monitor
ground water levels in the area of these natural resources.
Water Conservation Plan
The City has implemented may water conservation items which include the following:
✓ Water tier rate structure
✓ Water supply improvements — leak detection monitoring, leak repairs and valve
replacement
✓ Education efforts—WaterWise Program (www.ci.chanhassen.mn.us/waterwise)
✓ Rebates for high efficiency appliances and irrigation systems
✓ Real time meter reading
✓ Irrigation audits
✓ Enforcement of topsoil ordinance for new developments
An ordinance change that should be considered is limiting irrigation during daytime hours.
Irrigating between 10 am and 4 pm does very little to help turf and most of the water is lost
due to evaporation. Most communities around Chanhassen have adopted this ordinance.
Other water conservation ideas would be to encourage more landscaping features, planting
beds and trees, and less turf.
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