1. SCENARIO PLANNING FOR WATER AND WASTEWATER IN THE TRUCKEE MEADOWS NNWPC Agenda Item 9 Jeremy M. Smith, TMRPA Jim Smitherman, WRWC 8/3/2016

2. Outline  Background  Future growth outlook and spatial modeling  TMWA water use factors and model calculations  Water demand  Winter water use (proxy for wastewater)  Validation with observed data  Projection of future water demand and wastewater generation  Multiple scenarios  Spatially-enabled results

3. TMRPA Partnership with WRWC  GIS support for water and wastewater planning  Regional Water Management Plan  Regional Plan  Scenario planning  Consensus forecast  Spatial modeling of population and employment forecasts  TMRPA housing study  Pattern linked to cost of infrastructure

4. Washoe County Consensus Forecast  Assessment of forecasted population and employment growth; performed every 2 years by TMRPA to inform planning efforts across the region.  Sources  Nevada State Demographer  Truckee Meadows Water Authority  Woods and Poole  IHS – Global Insight

5. Washoe County Consensus Forecast

7. TMRPA Land Use Fabric Washoe County Parcels Existing Dwelling Units Final Maps Planned Unit Developm ents (PUDs) Tentative Maps (TMs) Tracking Current and Future Land Use WC Parcels Vacancy status Update DU and LU Class Update Final Maps PUDsTMs TMRPA LU Fabric Tracking residential development present and future potential Monthly Process for Updating Land Use Fabric

8. Spatial Allocation of Predicted Growth  Translate time series projections to spatial allocation of housing units and employment  Rule-based allocation model that uses an overall suitability score  Parcel-based  Dual-mode suitability model  Population  Employment  Model results can be aggregated to any geography  Traffic analysis zones  Wastewater treatment facility service areas  TMWA fee areas  Etc.

9. TMRPA Housing Study – 4 Scenarios  Extensive research and outreach on past housing trends (since 2000) and future outlooks on housing demand  Evaluation of 4 housing growth scenarios that simulate different spatial and temporal patterns  Scenario 1a Recent trends + Consensus Forecast  Scenario 1b Recent trends + EDAWN EPIC Forecast  Scenario 2a Compact development + Consensus Forecast  Scenario 2b Compact development + EDAWN EPIC Forecast  Learn more: www.tmrpa.org/housingstudy/ www.tmrpa.org/tmrpa-maps/

10. TMWA Total Water Use Coefficients Water use coefficients are taken directly from the TMWA 2016-2035 Water Resource Plan Weighted Average gives more weight to hydrobasins that have more units or meters in them Water Usage (1,000 gal) Hydro-basin Annual Usage GMWS GMWS Meters MMW (per customer) MMW (per unit)* Multi-Family Units RMWS Single-Family Units 83 149.6- 14.953 149.6213 85 326.9206360.036.0944162.017407 86 171.519191.019.123498.86079 87 632.35646421.042.149501144.578137 088E --351.635.28258.72093 088W 301.5-351.635.28258.72093 89 375.8-351.635.233368.71898 92 600.9270636.563.61231110.411710 Average 365.5-351.635.2-193.9- Weighted Average 611.0--42.4-149.9- *Assumes an average of 10 units per service

11. Methods – Water Demand Calculations Dwelling Unit Type Dwelling Units (Dwelling Units×Coefficient×Gal lons)÷365 days Total Water Demand (GPD) Single Family (weighted) 1 (1×149.9×1000)÷365 = 411 Multi-Family (weighted) 1(1×42.4×1000)÷365 = 116 Weighted Average FactorsStraight Average Factors Businesses Per Employee0.0750 Businesses Per Employee0.06055 Meters Per Business0.4862Meters Per Business0.3578 Non-Residential (GMWS) Unit (Units×Coefficient×Gall ons)÷365 days Total Water Demand (GPD) Non-Residential (employee- weighted) 1 Employee (1employee×0.075×0.4 9)(469.67×1000) ÷365 = 47 Gallons Per Employee Residential Non - Residential We chose a weighted-average approach to reflect the impact that more dwelling units and/or employees have on the overall average of water demand or wastewater generation We are still in process to compare our modeled water demand with existing demand values from TMWA

12. TMWA Indoor Water Use Coefficients Water use coefficients are derived from billing records from 2009-2015 Indoor usage only Winter months from December - March Weighted Average gives more weight to hydrobasins that have more units or meters in them Indoor Water Usage (1,000 gal) Hydro-basin Annual Indoor Usage GMWS GMWS Meters MMW (per customer) MMW (per unit)* Multi-Family Units RMWS Single-Family Units 83 170.4---3 213 85 265.8206325.132.594451.517407 86 201.919193.519.423464.46079 87 481.55646356.535.74950155.478137 088E ----836.02093 088W 116.2---830.52093 89 101.6---3324.01898 92 397.5270415.841.6123155.311710 Average 247.8-322.732.3-45.3- Weighted Average 469.67--35.7-54.0- *Assumes an average of 10 units per service

13. Methods – Wastewater Generation Calculations Dwelling Unit Type Dwelling Units (Dwelling Units×Coefficient×Gal lons)÷365 days Total Wastewater Generation (GPD) Single Family (weighted) 1 (1×53.992×1000)÷365 = 148 Multi-Family (weighted) 1 (1×35.661×1000)÷365 = 98 Weighted Average FactorsStraight Average Factors Businesses Per Employee0.0750 Businesses Per Employee0.06055 Meters Per Business0.4862Meters Per Business0.3578 Non-Residential (GMWS) Unit (Units×Coefficient×Gall ons)÷365 days Total Wastewater Generation (GPD) Non-Residential (employee- weighted) 1 Employee (1employee×0.075×0.4 9)(469.67×1000) ÷365 = 47 Gallons Per Employee Residential Non - Residential We chose a weighted-average approach to reflect the impact that more dwelling units and/or employees have on the overall average of water demand or wastewater generation Our initial calculations indicate that the weighted approaches had produced results more in line with observed flows

14. Regional Wastewater Generation – Validation with Observed (2015) Water Reclamation Facility (method) Total Wastewater Generation - Employee Factors Weighted (GPD) Average Day Annual Flow (GPD) TMWRF26,787,64026,330,000 STMWRF3,339,4013,000,000 RSWRF1,459,3021,400,000 CSWRF325,080297,000 LVWRF182,921260,000 Totals32,094,34431,287,000 Percentage of ADAF 102.58% Comparison Calculated Observed

15. Modeled Wastewater Generation – 5 Scenarios Scenario 1A Predicted Wastewater Generation (GPD) Scenario 2A Predicted Wastewater Generation (GPD) WRF2020202520302035WRF2020202520302035 TMWRF1,676,9383,193,7914,851,3286,232,927TMWRF1,727,8973,303,3874,998,5436,455,611 STMWRF427,155899,3921,361,6891,798,665STMWRF385,541814,6031,266,5681,637,415 RSWRF279,546591,609938,9021,135,789RSWRF258,876483,545807,3471,020,746 LVWRF75,878228,011423,068499,504LVWRF42,728202,810399,827505,412 CSWRF35,12375,303193,845462,476CSWRF35,12364,677140,464229,209 Totals2,494,6404,988,1057,768,83210,129,362Total2,450,1654,869,0217,612,7499,848,394 Scenario 1B Predicted Wastewater Generation (GPD) Scenario 2B Predicted Wastewater Generation (GPD) WRF2020202520302035WRF2020202520302035 TMWRF2,526,5024,325,9555,580,7216,198,728TMWRF2,656,0004,545,8285,836,8706,477,900 STMWRF803,6891,326,1181,724,7391,847,129STMWRF737,2661,207,6701,531,4251,621,047 RSWRF513,447893,1071,113,0551,157,483RSWRF387,441764,433990,3541,027,214 LVWRF206,365329,329489,186504,958LVWRF170,190313,543496,739513,169 CSWRF75,661255,382425,292454,366CSWRF76,583160,974219,522252,111 Total4,125,6647,129,8909,332,99310,162,665Total4,027,4806,992,4479,074,9109,891,442 Consensus Forecast Predicted Wastewater Generation (GPD) WRF20202025203020352040 TMWRF1,780,5113,303,0794,683,2565,776,5107,157,846 STMWRF392,505745,0361,156,4241,451,0151,906,712 RSWRF277,695507,381770,471899,6531,244,608 LVWRF76,145158,792389,012558,634815,367 CSWRF35,89694,07796,916128,329191,680 Totals2,562,7524,808,3657,096,0798,814,14111,316,212

16. Comparison – Scenario 1A vs. 2A 1A vs 2A TMWRFSTMWRFRSWRFLVWRFCSWRFTOTAL Scenario 121212121212 2020 1,676,9381,727,897803,689385,541279,546258,87675,87842,72835,123 2,871,1742,450,165 2025 3,193,7913,303,3871,326,118814,603591,609483,545228,011202,81075,30364,6775,414,8314,869,021 2030 4,851,3284,998,5431,361,6891,266,568938,902807,347423,068399,827193,845140,4647,768,8327,612,749 2035 6,232,9276,455,6111,798,6651,637,4151,135,7891,020,746499,504505,412462,476229,20910,129,3629,848,394

18. Conclusions  These data are now available to assist Jim Smitherman with the update of the Regional Water Management Plan  We have worked closely to ensure Jim’s needs are met and that planning efforts across the region are aligned  We have the capacity to evaluate other scenarios and to conceptualize differences using other geographic boundaries (e.g. fee areas)  Although this delivery marks the end of our interlocal agreement around scenario planning, this is not the end of our relationship  We are committed to continued collaboration with water and wastewater staff to calibrate model assumptions and to evaluate alternate scenarios, especially as our regional outlook of the future changes  Capability for online dissemination of these data (and other related data) via our GIS map viewer products  Password protected access  Some printing and map composition functionality  Access to tabular data