Scenario Planning for Water and Wastewater in the Truckee Meadows WRWC Agenda Item 9 Jeremy M. Smith, TMRPA Jim Smitherman, WRWC 8/17/2016

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

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

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

Washoe County Consensus Forecast

Washoe County Consensus Forecast

Tracking Current and Future Land Use Tracking residential development present and future potential Tracking employees by business location TMRPA Land Use Fabric Washoe County Parcels Existing Dwelling Units Final Maps Planned Unit Developments (PUDs) Tentative Maps (TMs) Each month we download the most recent Washoe County Parcel data in order to update land use and dwelling unit counts. We are also able to digitized in (bubble map) parcels from lot block plans from Planned Unit Developments and Tentative Maps. Final maps are record straight from the assessor parcel data. Monthly Process for Updating Land Use Fabric WC Parcels Vacancy status Update DU and LU Class Update Final Maps PUDs TMs TMRPA LU Fabric

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.

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/

TMWA Total Water Use Coefficients 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 - 14.95 3  149.6 213 85 326.9 206 360.0 36.0 944 162.0 17407 86 171.5 19 191.0 19.1 234 98.8 6079 87 632.3 5646 421.0 42.1 49501 144.5 78137 088E 351.6 35.2 8 258.7 2093 088W 301.5 89 375.8 33 368.7 1898 92 600.9 270 636.5 63.6 1231 110.4 11710 Average 365.5 193.9 Weighted Average 611.0 42.4 149.9 *Assumes an average of 10 units per service We worked with Shawn Stoddard and Laine Christman to obtain TMWA indoor water use coefficients. GMWS represents commercial use while MMW represents multi-family and RMWS represents single family. We utilized the straight average which is the second row from the bottom and a weighted average which gives more weight to hydrobasins with more units in them. We then applied these coefficients to each parcel to calculate wastewater generation. 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

Methods – Water Demand Calculations Residential Non - Residential Dwelling Unit Type Dwelling Units (Dwelling Units×Coefficient×Gallons)÷365 days Total Water Demand (GPD) Single Family (weighted) 1 (1×149.9×1000)÷365 = 411 Multi-Family (weighted) (1×42.4×1000)÷365 = 116 Non-Residential (GMWS) Unit (Units×Coefficient×Gallons)÷365 days Total Water Demand (GPD) Non-Residential (employee- weighted) 1 Employee (1employee×0.075×0.49)(611.0×1000) ÷365 = 62 Gallons Per Employee 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 This table shows the formulas that use the coefficients shown from the previous page. We used a straight average and a weighted average for each WRF. The weighted average for residential gives more weight to parcels with greater amounts of single family and multi-family units in them. The weighted average for industrial gives more weight to parcels with a greater number of businesses and employees on it. Weighted Average Factors Straight Average Factors Businesses Per Employee 0.0750 0.06055 Meters Per Business 0.4862 0.3578

TMWA Indoor Water Use Coefficients 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 85 265.8 206 325.1 32.5 944 51.5 17407 86 201.9 19 193.5 19.4 234 64.4 6079 87 481.5 5646 356.5 35.7 49501 55.4 78137 088E 8 36.0 2093 088W 116.2 30.5 89 101.6 33 24.0 1898 92 397.5 270 415.8 41.6 1231 55.3 11710 Average 247.8 322.7 32.3 45.3 Weighted Average 469.67 54.0 *Assumes an average of 10 units per service We worked with Shawn Stoddard and Laine Christman to obtain TMWA indoor water use coefficients. GMWS represents commercial use while MMW represents multi-family and RMWS represents single family. We utilized the straight average which is the second row from the bottom and a weighted average which gives more weight to hydrobasins with more units in them. We then applied these coefficients to each parcel to calculate wastewater generation. 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

Methods – Wastewater Generation Calculations Residential Non - Residential Dwelling Unit Type Dwelling Units (Dwelling Units×Coefficient×Gallons)÷365 days Total Wastewater Generation (GPD) Single Family (weighted) 1 (1×53.992×1000)÷365 = 148 Multi-Family (weighted) (1×35.661×1000)÷365 = 98 Non-Residential (GMWS) Unit (Units×Coefficient×Gallons)÷365 days Total Wastewater Generation (GPD) Non-Residential (employee- weighted) 1 Employee (1employee×0.075×0.49)(469.67×1000) ÷365 = 47 Gallons Per Employee 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 This table shows the formulas that use the coefficients shown from the previous page. We used a straight average and a weighted average for each WRF. The weighted average for residential gives more weight to parcels with greater amounts of single family and multi-family units in them. The weighted average for industrial gives more weight to parcels with a greater number of businesses and employees on it. Weighted Average Factors Straight Average Factors Businesses Per Employee 0.0750 0.06055 Meters Per Business 0.4862 0.3578

Regional Wastewater Generation – Validation with Observed (2015) Calculated Observed Water Reclamation Facility (method) Total Wastewater Generation - Employee Factors Weighted (GPD) Average Day Annual Flow (GPD) TMWRF 26,787,640 26,330,000 STMWRF 3,339,401 3,000,000 RSWRF 1,459,302 1,400,000 CSWRF 325,080 297,000 LVWRF 182,921 260,000 Totals 32,094,344 31,287,000 Comparison Percentage of ADAF 102.58%

Modeled Wastewater Generation – 5 Scenarios Scenario 1A Predicted Wastewater Generation (GPD) Scenario 2A WRF 2020 2025 2030 2035 TMWRF 1,676,938 3,193,791 4,851,328 6,232,927 1,727,897 3,303,387 4,998,543 6,455,611 STMWRF 427,155 899,392 1,361,689 1,798,665 385,541 814,603 1,266,568 1,637,415 RSWRF 279,546 591,609 938,902 1,135,789 258,876 483,545 807,347 1,020,746 LVWRF 75,878 228,011 423,068 499,504 42,728 202,810 399,827 505,412 CSWRF 35,123 75,303 193,845 462,476 64,677 140,464 229,209 Totals 2,494,640 4,988,105 7,768,832 10,129,362 Total 2,450,165 4,869,021 7,612,749 9,848,394 Scenario 1B Scenario 2B 2,526,502 4,325,955 5,580,721 6,198,728 2,656,000 4,545,828 5,836,870 6,477,900 803,689 1,326,118 1,724,739 1,847,129 737,266 1,207,670 1,531,425 1,621,047 513,447 893,107 1,113,055 1,157,483 387,441 764,433 990,354 1,027,214 206,365 329,329 489,186 504,958 170,190 313,543 496,739 513,169 75,661 255,382 425,292 454,366 76,583 160,974 219,522 252,111 4,125,664 7,129,890 9,332,993 10,162,665 4,027,480 6,992,447 9,074,910 9,891,442 Consensus Forecast 2040 1,780,511 3,303,079 4,683,256 5,776,510 7,157,846 392,505 745,036 1,156,424 1,451,015 1,906,712 277,695 507,381 770,471 899,653 1,244,608 76,145 158,792 389,012 558,634 815,367 35,896 94,077 96,916 128,329 191,680 2,562,752 4,808,365 7,096,079 8,814,141 11,316,212

Comparison – Scenario 1A vs. 2A TMWRF STMWRF RSWRF LVWRF CSWRF TOTAL Scenario 1 2 2020 1,676,938 1,727,897 803,689 385,541 279,546 258,876 75,878 42,728 35,123 2,871,174 2,450,165 2025 3,193,791 3,303,387 1,326,118 814,603 591,609 483,545 228,011 202,810 75,303 64,677 5,414,831 4,869,021 2030 4,851,328 4,998,543 1,361,689 1,266,568 938,902 807,347 423,068 399,827 193,845 140,464 7,768,832 7,612,749 2035 6,232,927 6,455,611 1,798,665 1,637,415 1,135,789 1,020,746 499,504 505,412 462,476 229,209 10,129,362 9,848,394

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

Questions?