Managing Demands

1
Managing Demands

• Reducing unaccounted-for water manages demands
  maximizes revenues
• Leak detection programs save you money

2
Unaccounted-for Water

• Is the difference between the water entering the
  supply system and the water used.

3
Unaccounted-for water varies widely among
communities
3-65
4
Not all unaccounted-for water is bad

• Authorized unmetered use
• fire fighting
• main flushing
• public area landscaping
• others

5
Unaccounted-for water is also comprised of water
loss

• Water Loss
• leaks
• malfunctioning controls
• theft
• illegal connections
• inaccurate meters
• Lost water does not produce revenue or provide a
  beneficial use

6
Some leaks are easy to find
Abandoned Service Line
7
Some leaks stay underground
Subsurface (blind) leak leaking into the sewer
8
Some leaks stay underground
Subsurface (blind) leak formed cavity below the
street
9
Leak Detection (Sound Survey) Programs should be
part of an annual operations budget

• Leaks get bigger with age
• Repairing leaks reduces growing water loss
• Reduces overtime costs associated with
  unscheduled repairs
• Reduces the amount of water to purchase
• Your customers appreciate well maintained systems

10
Sound Survey Programs focus on reducing water loss

• Acoustic amplifying instruments used to detect
  water leaks

11
Sound Survey Programs focus on reducing water loss

• Leaks located by sounding hydrants, valves, other
  direct contacts to system
• Leaks are pinpointed with correlation equipment

12
Leak Detection Programs

• Programs should be focused on the dollars saved
  not on percentage lost
• Typical program consists of a two person crew
• 5 miles/day
• 80 Sounding
• 20 Correlating

13
Leak Detection Program Example - Anytown, MI

• Cost of Water 7.95/MCF
• Distribution Pipe 462 Miles
• Water Purchased 793,140 MCF/yr
• Average Day Demand 16.25 MGD
• Total Cost of Water 6,303,935/yr
• U-f Water 15
• U-f Water due to Leaks 5
• U-f Water due to Leaks 315,197/yr

14
Leak Detection Program Example

• Leak Detection Cost
• Sound Survey 103,488
• Correlation 18,480
• Total Cost 121,968
• Savings 193,229 Every Year!
• savings from potable water only

15
The City of Detroit program is multi-purpose

• 3500 miles of distribution mains
• Four Year Program
• Leak Detection Program
• Sound Survey
• Map Corrections
• Exercise Valves
• Generate Work Orders

16
The City of Detroit program is multi-purpose

• Summary of Program to Date
• Cost of Program 875,000
• Savings 2.2M
• Volume of Water Loss 6.6 MGD
• Map Corrections 351
• System Corrections 900 Valves in wrong position

17
Detroits program has been proactive in reducing
water loss
DWSD Stopped Leak Detection Program
DWSD Restarts Leak Detection Program
18
How should I get started?

• Simple Water Audit
• Quantify Beneficial Uses of Unaccounted-for Water
• Quantify Unaccounted-for Water Attributable to
  Water Loss
• Estimate Cost of Water Loss