SPDSS_Task66-2_CollectDevelopMunicipalIndustrialConsumptiveUseEstimates

• Title: SPDSS Task 66.2 - Collect and Develop Municipal and Industrial Consumptive Use Estimates
• Description: This memorandum presents the general approach used to develop municipal and industrial consumptive use for the CU and Losses Summary Report and estimate indoor and outdoor water demands, consumptive use, and return flows for SPDSS modeling efforts.
• Decision Support - Doc Type: Task Memorandum
• Date: 11/14/2007
• DSS Category: Consumptive Use
• DSS: South Platte
• Basin: South Platte
• Contract/PO #: C153954
• Grant Type: Non-Reimbursable
• Bill Number: SB01-157, HB02-1152, SB03-110, HB04-1221, SB05-084, HB06-1313, SB07-122
• Prepared By: Leonard Rice Engineering

The total water demand (2000) estimated for combined municipal and SSI users in the SPDSS
study area is approximately 758,000 acre-feet per year. The total consumptive use estimated for
combined municipal and SSI users in the SPDSS study area is approximately 295,000 acre-feet
per year, or about 40 percent of the water demand.
3. StateMod Modeling Recommendations
One-hundred percent of the municipal and industrial uses will be represented in the future
SPDSS Water Resources Planning Model (StateMod) efforts. As recommended above, municipal
demand nodes should be represented with two sets of nodes - in-house and outside -due to the
different amount, timing, and location of return flows associated with these portions of the
municipal water demand. Unless otherwise specified, operating rules and water rights will meet
in-house demands first followed by outside demands, based on conversations with municipalities
regarding relative priorities in water resources operations. Forty-four (44) total sets of model
nodes are recommended for representing municipal water users in the SPDSS Water Resources
Planning Model, as summarized in Table 9 and Figure 6 at the end of the memorandum.
Self-supplied industrial demands should be represented with individual nodes since the majority
of their water demands reflect a single use (e.g., cooling water or snowmaking water). Nine (9)
total model nodes are recommended for representing self-supplied industrial water users in the
SPDSS Water Resources Planning Model, as summarized in Table 10 and Figure 6 at the end of
the memorandum.
Municipal Water users
• In-house demands should be modeled as a constant over the year; these demand rates vary
year-by-year based on population (see Table 2)
• In-house CU rates should be estimated to be 5 percent for municipal populations and 10
percent for unincorporated populations
• Outside demands should be distributed on a monthly basis based on a typical distribution of
bluegrass crop irrigation requirements (see Table 4)
• Outside CU rates should be estimated to be 83 percent (i.e., 83 percent efficiency)
The 44 sets of municipal water user nodes are broken down as follows (see Table 9 and
Figure 6):
• Ten sets of model nodes for key municipal water users (identified as `Key Municipality' in
Comments field of Table 9)
• Sixteen sets of model nodes for aggregate municipal water users, using Structure IDs of
WD_AMPxxx signifying Water District Aggregate Municipal Population
o Fifteen sets of nodes representing municipalities with population data that have not been
designated as `key' (e.g., Federal Heights, Brighton, Erie, Lafayette, Black Hawk, etc.)
o One set of nodes for aggregated municipal well water user supplied by Denver Basin
Wells (O1_AMP001)
• Seventeen sets of model nodes for aggregate unincorporated water users, using Structure IDs
of WD_AUPxxx signifying Water District Aggregate Unincorporated Population
o Sixteen sets of nodes representing unincorporated population within counties not
assigned to a key municipal water user or aggregate municipal water user
Task 66.2 Memorandum.doc Page 18 of 26