Castle Pines North WC Plan2007

• Project Type: Water Conservation Plan
• Applicant: Castle Pines North Metropolitan District
• Project Name: Water Conservation Plan
• Title: Castle Pines North Metropolitan District Water Conservation Plan
• Date: 8/1/2006
• County: Douglas
• Water Conservation - Doc Type: Complete Plan

CDM

Section 4
Proposed Facilities

A conventional or advanced water treatment plant (depending upon water quality)
would treat water stored in Rueter Hess, prior to conveyance to the District service
area. Another option would be to capture treated wastewater return flow credits
downstream of the wastewater discharge and convey the water to Rueter Hess for
storage. A pipeline would be constructed from downstream of the wastewater outlet
to Rueter Hess. Surface water could also be used to recharge the groundwater under
an aquifer storage and recovery (ASR) concept. This is described in more detail in
Section 4.3. The IWRP will provide a detailed evaluation of all these alternatives.

Approach

Given the number of water supply alternatives and the lack of knowledge on what
actions will be taken to acquire surface water supplies, specific information regarding
future costs and timing of when renewable surface water may come online is
unknown. The costs of a future surface water supply will be further influenced by the
District's investment decisions as well as the phasing of when and how the surface
supplies are brought online. Consequently, for the purposes of this Plan, the cost
analyses assume that the District will continue to rely on groundwater and the effects
of a renewable surface water supply is addressed qualitatively.

This Plan incorporates a planning period of 10 years from 2006-2015. A 10-year
planning period was chosen for the following reasons:

. Buildout is projected to occur in 2011. This planning period provides an adequate
period of time to capture demands at build out.

. Ten years provides a suitable time period to assess the effects of conservation
measures for Castle Pines North.

. It is not necessary to go beyond 10 years. The Colorado Water Conservation Board
requires that covered Conservation Plan be updated at a minimum of 7 years. The
update of this Plan will be able to capture much more information on the costs of
surface water supplies and conservation savings, given that there will be much
more data available.

Water Supply Improvements
Several improvements to the existing well system are planned for 2006 and 2007. In
2006 wells A-I and A-3 are to be rehabilitated. In 2007, well, A-5 is to be put online.
This well was originally drilled as a directional well. The well did not perform as
anticipated and experienced a number of construction related delays and issues;
however, data have shown that yields may be attained from the vertical portion of the
shaft. The horizontal portion is to be sealed off, enabling water to be withdrawn from
the vertical portion.

Costs for the use of groundwater during the planning period are shown in Table 4-1.
The capital and O&M costs are summed for each year and adjusted for escalation and
discount rates to obtain present value costs. Operation costs were adjusted for the
increase in water demand (See Section 3.3) and electricity costs.

4-3

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