Appendix E Distribution System Analysis

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Water System and Resources Plan Appendices

Pasadena Water & Power May 2020

Appendix E Distribution System Analysis

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Water System and Resources Plan Appendices

Pasadena Water & Power May 2020

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Water System and Resources Plan Distribution System Analysis

Pasadena Water & Power E-1 May 2020

APPENDIX E. DISTRIBUTION SYSTEM ANALYSIS

Appendix E provides information on the process used as part of the Water System and Resources Plan (WSRP) to assess PWP’s distribution system capacity

The distribution system capacity analysis used the hydraulic model to evaluate system pressures, adequacy of pressure zones, and reliability. Tables E-1 and E-2 list each scenario run (using the scenario title as listed in the model), demand conditions, pipe set, and purpose for running the scenario under current and future demands. Note that the hydraulic model assumes that the supply portfolio used is unchanged from the baseline described in the WSRP, relying on existing groundwater wells and imported water connections. Figure E-1 provides the resulting hydraulic deficiencies under current conditions, while Figure E-2 provides additional hydraulic deficiencies under future conditions (assuming hydraulic deficiencies under existing conditions are addressed). Both of these figures assume a minimum pipe roughness coefficient of 80.

In addition to the pipeline network assessment performed using hydraulic modeling, a hydraulic assessment was performed to analyze the capacity of reservoirs and booster stations under current and future conditions. This hydraulic assessment was completed using a spreadsheet exercise that incorporated demand within each pressure zone, reservoir storage capacity, booster station capacity, supply inputs within each pressure zone and capacity requirements for reservoirs and booster stations within each pressure zone. Demand and supply within each pressure zone was exported from the hydraulic model. The capacity surplus or deficit was determined within each pressure zone, then any areas of deficit were analyzed to determine whether surplus from higher pressure zones could be used to offset the deficit. Based on this analysis, recommendations were developed for above-ground infrastructure improvements.

Tables E-3 and E-4 provide a summary of the booster station capacity by pressure zone for current and future demands, as well as the service-area wide total, with and without MWD imported water supply. These results indicate that, while some pressure zones show negative values, the service area as a whole has sufficient booster station capacity to provide service to all pressure zones, and that neighboring pressure zones have capacity to support zones with insufficient capacity.

Tables E-5 and E-6 provide a summary of the storage reservoir capacity, indicates that PWP has a surplus storage capacity for the system as a whole. While some individual pressure zones show a storage deficit, most are connected to zones of higher pressure via a pressure sustaining valve (PSV) that allows for the automatic cascading of water from the higher-pressure zone to the lower-pressure zone to meet demand. The only zone with a deficit that isn’t connected to a higher-pressure zone is the Eagle Rock Pressure Zone located in the southwestern part of PWP’s service area.

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Table E-1: Hydraulic Modeling Scenarios Run Using Current Demands

Scenario Demand

Conditions Pipe Set Purpose

EX_ADD_ASSESSMENT

ADD Existing pipes Check for maximum pressure violations

EX_MDD_ASSESSMENT

MDD (includes PHD)

Existing pipes Check for minimum pressure and maximum velocity violations.

EX_MDD_FF_ASSESSMENT

MDD Existing pipes Check for fire flow availability and related deficiencies.

MDD_FF_MIN_C-80 MDD

Existing pipes with minimum Hazen Williams factor set to 80

Check for fire flow availability and related deficiencies.

MDD_FF_MIN_C-90 MDD

Existing pipes with minimum Hazen Williams factor set to 90

Check for fire flow availability and related deficiencies.

EX_CIP_DEV_ADD ADD Existing pipes + projects to address existing deficiencies

Develop projects and confirm projects address identified deficiencies.

EX_CIP_DEV_MDD MDD (includes PHD)

Existing pipes + projects to address existing deficiencies


EX_CIP_DEV_MDD_FF

MDD Existing pipes + projects to address existing deficiencies


EX_CIP_DEV_MDD_FF_C-80



EX_CIP_DEV_MDD_FF_C-90



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Table E-2: Hydraulic Modeling Scenarios Run Using Future Demands

Scenario Demand Conditio

ns Pipe Set Purpose

FUT_ADD_ASSESSMENT

ADD

Future pipes (assumes existing pipes + all projects to address existing deficiencies)

Check for maximum pressure violations under future demands conditions

FUT_MDD_ASSESSMENT

MDD (includes PHD)

Future pipes

Check for minimum pressure and maximum velocity violations with under future demands conditions.

FUT_MDD_ASSESSMENT

MDD Future pipes Check for fire flow availability and related deficiencies under future demand conditions.

FUT_CIP_DEVELOPMENT

MDD (includes PHD)

Future pipes + projects to address future deficiencies


FUT_NEW_SUPPLY_PORTFOLIO

MDD Future pipes

Check for minimum pressure and maximum velocity violations with new supply portfolio and future demands.

FUT_NEW_SUPPLY_ADD_ASSESS

ADD Future pipes Check for maximum pressure violations with new supply portfolio and future demands.

FUT_NEW_SUPPLY_ADD_MWD_OOS

ADD Future pipes

Check system ability to meet demands for 7 days under future demand conditions with new supply portfolio and all MWD connections out of service.

FUT_NEW_SUPPLY_ADD_WELLS_OOS

ADD Future pipes

Check system ability to meet demands for 7 days under future demand conditions with new supply portfolio and wells out of service.

FUT_NEW_SUPPLY_MDD_WELLS_OOS

MDD Future pipes

Check system ability to meet demands for 7 days under future demand conditions with new supply portfolio and wells out of service.

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Figure E-1: Modeled Flow Deficiencies under Current Conditions

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Pasadena Water and Power E-5 May 2020

Figure E-2: Modeled Flow Deficiencies under Future Conditions

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Table E-3: Booster Station Capacity Analysis Results under Current Demands

Pressure Zone

Available Capacity w/ MWD* (gpm)

Available Capacity w/o MWD* (gpm)

Max Day Demand

Exst (gpm)

Difference w/ MWD (gpm)

Difference w/o MWD

(gpm)

Allen 2,200 2,200 1,198 1,002 1,002

Allen Hydro 300 300 9 291 291

Annandale 1,225 1,225 603 622 622

Calaveras 23,000 23,000 8,980 14,020 14,020

Don Benito 560 560 306 254 254

Eagle Rock*** 3,400 2,700 1,282 2,118 1,418

Lida 400 400 206 194 194

Gould 1,000 1,000 802 198 198

Mirador 815 815 111 704 704

Murray Hydro 300 300 37 263 263

Sheldon 13,300 13,300 7,897 5,403 5,403

Sunset** 33,032 7,000 15,011 18,020 -8,012

Total 87,252 60,520 36,445 50,807 24,075

* Total capacity minus the largest pump in the pressure zone

**Includes Woodbury, Wadsworth, Twombly, and Chapman wells. Also includes P-1, P-2, and P-3 MWD connections in w/ MWD capacity

***P-5 MWD connection not included as it is the largest pump in the zone in w/ MWD capacity

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Pasadena Water and Power E-7 Appendix E May 2020

Table E-4: Booster Station Capacity Analysis Results under Future Demands

Pressure Zone Available Capacity w/ MWD* (gpm)

Available Capacity w/o MWD* (gpm)

Max Day Demand

2045 (gpm)

Difference w/ MWD (gpm)

Difference w/o MWD

(gpm)

Allen 2,200 2,200 1,258 942 942

Allen Hydro 300 300 11 289 289

Annandale 1,225 1,225 645 580 580

Calaveras 23,000 23.000 9,540 13,460 13,460

Don Benito 560 560 324 236 236

Eagle Rock*** 3,400 2,700 1,332 2,068 1,368

Lida 400 400 230 170 170

Gould 1000 1,000 878 122 122

Mirador 815 815 131 684 684

Murray Hydro 300 300 39 261 261

Sheldon 13,300 13,300 8,383 4,917 4,917

Sunset** 33,032 7,000 15,808 17,224 -8,808

Total 87,252 60,520 38,579 48,673 21,941

* Total capacity minus the largest pump in the pressure zone

**Includes Woodbury, Wadsworth, Twombly, and Chapman wells. Also includes P-1, P-2, and P-3 MWD connections in w/ MWD capacity

***P-5 MWD connection not included as it is the largest pump in the zone in w/ MWD capacity

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Table E-5: Reservoir Hydraulic Capacity Analysis Results under Current Demands

Existing Demand Storage Requirements (MG)

Pressure Zone Average Day

Demand (mgd) Maximum Day Demand (mgd)

Highest Zone FF Requirement

Fire Flow (Highest FF

Req)

Operational (30% of MDD)

Emergency (50% of MDD)

Storage Required

Storage Available

(MG)

Surplus/ Deficit

Sufficient Storage?

Allen Hydro* 0.01 0.01 Single-Family Res 1,500 gpm/2 hours

0.18 0.004 0.01 0.19 4.10 3.91 Yes

Allen (w/ Allen Red. 1 and 2)

0.90 1.72 Commercial

3,000 gpm/3 hours 0.54 0.52 0.86 1.92 4.10 2.18 Yes

Annandale (w/ Annandale Red.)

0.45 0.87 Multi-Family Res

1,500 gpm/2 hours 0.18 0.26 0.43 0.87 0.64 -0.23 No

Calaveras (w/ Calaveras Red. East and West)

6.73 12.93 High Schools

4,000 gpm/4 hours 0.96 3.88 6.47 11.31 20.40 9.09 Yes

Don Benito (w/ Don Benito Red.)


3,000 gpm/3 hours 0.54 0.13 0.22 0.89 1.40 0.51 Yes

Eagle Rock 0.96 1.85 Commercial

3,000 gpm/3 hours 0.54 0.55 0.92 2.02 0.95 -1.07 No

Lida 0.15 0.30 Single-Family Res 1,500 gpm/2 hours

0.18 0.09 0.15 0.42 0.43 0.01 Yes

Gould (w/ Gould Red.)

0.60 1.15 JPL

4,000 gpm/4 hours 0.96 0.35 0.58 1.88 3.00 1.12 Yes

Mirador (w/ Mirador Red.)


1,500 gpm/2 hours 0.18 0.05 0.08 0.31 1.00 0.69 Yes

Murray Hydro** 0.03 0.05 Single-Family Res 1,500 gpm/2 hours

0.18 0.02 0.03 0.22 20.40 2.18 Yes

Sheldon 5.92 11.37 City Hall

5,000 gpm/5 hours 1.5 3.41 5.69 10.60 11.83 1.23 Yes

Sunset (w/ Sunset Red, Sierra Madre Villa, Sierra Madre Villa Red.)

11.24 21.62 PCC

4,000 gpm/4 hours 0.96 6.49 10.81 18.25 65.33 47.08 Yes

Total 27.30 52.48 6.90 15.74 26.24 48.88 109.09 60.20

* Allen Hydro receives available storage from Allen reservoir pressure zone

** Murray Hydro receives available storage from Calaveras pressure zone

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Table E-6: Reservoir Hydraulic Capacity Analysis Results under Future Demands

2045 Demand Storage Requirements (MG)

Pressure Zone Ave. Day Demand

(mgd)

Max. Day Demand

(mgd)

Highest Zone FF Requirement

Fire Flow (Highest FF

Req)

Operational (30% of MDD)

Emergency (50% of MDD)

Storage Required

Storage Available

(MG)

Surplus/ Deficit

Sufficient Storage?

Allen Hydro* 0.01 0.02 Single-Family Res 1,500 gpm/2 hours

0.18 0.006 0.01 0.20 4.10 3.90 Yes

Allen (w/ Allen Red. 1 and 2)


3,000 gpm/3 hours 0.54 0.54 0.91 1.99 4.10 2.11 Yes

Annandale (w/ Annandale Red.)


1,500 gpm/2 hours 0.18 0.28 0.46 0.92 0.64 -0.28 No

Calaveras (w/ Calaveras Red. East and West)

7.15 13.73 High Schools

4,000 gpm/4 hours 0.96 4.12 6.87 11.94 20.40 8.46 Yes

Don Benito (w/ Don Benito Red.)


3,000 gpm/3 hours 0.54 0.14 0.24 0.92 1.40 0.48 Yes

Eagle Rock 1.00 1.92 Commercial

3,000 gpm/3 hours 0.54 0.58 0.96 2.08 0.95 -1.13 No

Lida 0.17 0.33 Single-Family Res 1,500 gpm/2 hours

0.18 0.10 0.17 0.44 0.43 -0.01 No

Gould (w/ Gould Red.)

0.66 1.26 JPL

4,000 gpm/4 hours 0.96 0.38 0.63 1.97 3.00 1.03 Yes

Mirador (w/ Mirador Red.)


1,500 gpm/2 hours 0.18 0.06 0.10 0.33 1.00 0.67 Yes

Murray Hydro** 0.03 0.06 Singlei-Family Res 1,500 gpm/2 hours

0.18 0.02 0.03 0.23 20.40 20.17 Yes

Sheldon 6.28 12.07 City Hall

5,000 gpm/5 hours 1.5 3.62 6.04 11.16 11.83 0.67 Yes

Sunset (w/ Sunset Red, Sierra Madre Villa, Sierra Madre Villa Red.)

11.84 22.77 PCC

4,000 gpm/4 hours 0.96 6.83 11.39 19.18 65.33 46.15 Yes

Total 28.91 55.55 6.90 16.67 27.78 51.34 109.09 57.75

* Allen Hydro receives available storage from Allen reservoir pressure zone

** Murray Hydro receives available storage from Calaveras pressure zone

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Documents

Appendix E Distribution System Analysis