Centennial WSD 1996 WCPlan

• Project Type: Water Conservation Plan
• Project Name: Centennial Water & Sanitation District Water Conservation Plan
• Title: Water Management Study
• Date: 8/10/1995
• County: Arapahoe
• Water Conservation - Doc Type: Complete Plan

I
1
I
I
1
I
I
I
I

I
I
I
I
I
-I
I
I
)

7-4

To arrive at total water savings, the unit savings are multiplied by the total population
projected to be impacted by the measure. Included in the calculation of total population
impacted is the expected penetration of a given market. The expected penetration is typically
expressed as a percentage of the total available market, less. an attrition rate for the percentage
of homes that will replace conserving plumbing fIxtures or discontinue conservation practices
over time.

This calculated water savings will be used for the development of dollar savings and costs
for both the customer and the District. These estimates are developed on the best available data,
but future planning should remain flexible in the event that actual savings are greater or less than
predicted.

Wastewater Savings. Wastewater savings or flow reduction is calculated as equal to
the interior water savings produced by conservation measures. Therefore, it is directly linked
to the water savings methodology indicated above. Additional measures that can be used to
decrease wastewater flows and loads, but not addressed in this report, include: waste
minimization, industrial pretreatment, and infiltration and inflow control to the collection system.
These programs are carried out by the District independent of their water conservation program.

Monetary Benefits. Dollar savings for the District are based upon the calculation of
water and wastewater saved, multiplied by the respective marginal costs of water treatment and
conveyance, and wastewater collection and treatment. These saved costs or benefIts have been
detennined to be $322 per million gallons and $198 per million gallons for water and.
wastewater, respectively. These benefIts are analyzed for a 5-year period and calculated as a
Present Worth cost.

Other monetary benefIts are detennined by associating the savings of a measure with the
implementation of facility improvements and other capital costs. These benefIts were not
included as part of the Present Worth analysis.

For the customer, the benefits would be based 00.- tbefeduction 1:1. rates associated with
the water and wastewater savings, and any related energy savings and are shown as an annual
savings.

Monetary Costs. As with the monetary benefIts, cost impacts are associated with
particular measures to detennine the Present Worth costs. For the District, these are made up
of costs to implement the measures, lost revenues, and other related costs. For the customer,
costs would include those for any fIxtures, parts, and repair bills associated with a particular
measure.

Customer costs and the resultant benefIt to cost ratios for the District help to determine
which measures have the greatest positive impact. For the benefIt to cost analysis, the District's
monetary benefIts are divided by the total costs for the 5-year evaluation.

21-6651