PROJ00156

• Contract/PO #: C153721
• Contractor Name: Lyons, Town of
• Contract Type: Loan
• Water District: 5
• County: Boulder
• Loan Projects - Doc Type: Feasibility Study

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System Demands

System demands are expressed as statistics for estimated average day usage and peak
day usage for the existing demand and future demand. See Table 3 for water production data.
The town estimates the population served at 1350, as previously stated. Data provided by the
town on analysis of metered and unmetered customers for 1993 was also reviewed. As a
result, the following are the statistics used in this report:

Gross capita annual average demand = 227 gal/cap/day (all usage)
Number of Single family equivalent tap (SFE) =
125 metered residential
+ 303 unmetered residential
+ 104 (commercial, schools, town, leakage, other)
= 532 existing SFE taps to the system.
Capita per SFE = 2.5 (1350 cap/532 SFE = 2.5, reasonable)
Peaking factor = max day/avg day = 4.0 (1990 data shows 3.99)

Using the above data, (227 gal x 532 SFE x 2.5 cap/SFE x 4.0 pf)/106 = 1.2 MGD. This
result represents the total maximum demand condition to be placed on the existing system; it
compares well with the 1.234 MGD observed in 1990 (Table 3) and is used throughout this
study to evaluate the adequacy of the town's water system.

Water System Model and Results of Analysis

To analyze the existing water system, RED developed a computer model of the system
using the CyberNet Version 2.16 analysis package. Components such as pipelines, pipe
junctions (called "nodes"), valves, supplies, demands and storage tanks are input into the
model. The nodes are usually distribution points, such as fire hydrants or taps, or points of
demand on the distribution system.

Existing system mapping data supplied by the town was entered into the model to construct the
storage and distribution system network. The existing pipe diameters range from 2 inches to
12 inches. The resulting network is a close approximation of the existing system. Because the
majority of the existing piping system was old and may have tuberculation, i.e., internal
deposits obstructing flow, a coefficient of roughness, or C factor, of 90 was assumed in the
model for the existing system piping. Newer pipe is typically represented by a C factor of
140. These C values are used in calculating the friction losses within the piping system. A
pipe with a C factor of 90 will typically have approximately twice the friction loss as a pipe
with a C factor of 140.

Once the preliminary computer analysis was performed for fire flows, the resulting results
were compared against measured fire flows at various hydrants throughout the system. The

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