Merced District Hydrologic and Hydraulic Operations (MIDH2O) Model September 05, 2018

Marco Bell, Merced Irrigation District Bibek Joshi, Dewberry Objective

• Introduce HEC-RTS • Benefits of MIDH2O

2 | | MIDH2O September 05, 2018 MIDH2O Origins

• 2015 USBR WaterSMART – Drought Resiliency Project Grant

• MIDH2O is the Merced Irrigation District Hydrologic and Hydraulic Operations Model

• MIDH2O is a tool to assist MID in the management of the Merced flows, operation of New Exchequer and regulate MID irrigation diversions.

• MIDH2O can serve as a decision support tool for power generation and help link water and power operations to the hydro power market.

• Based on HEC-RTS

3 | | MIDH2O September 05, 2018 Merced Irrigation District

• Established in 1919 * • Store and distribute water for irrigation • Total irrigable lands in MID: 138,000 acres • 825 miles of water distribution facilities (earth lined, concrete lined channels and pipes) • Also provides water for domestic uses, provide control, hydroelectric power generation, and recreation • Provides water to approximately 2,200 farmers in Merced County and affordable electricity to 7,500 residences and business • Owns and operates New Exchequer and McSwain , reservoirs and hydroelectric facilities

* http://www.mercedid.com/index.cfm/about/history‐of‐the‐district/

4 | | MIDH2O September 05, 2018 Merced Irrigation District

5 | | MIDH2O September 05, 2018 Watershed • of San Joaquin River • Area: 1,267 square miles (1,037 square miles at New Exchequer Dam) • Elevation Range: 52 – 13,090 ft (535 square miles above 5,000 feet) • Upper watershed in Yosemite National Park

6 | MIDH2O September 05, 2018 HEC-RTS

• Publicly available software from HEC

• Software system supporting data acquisition, visualization, and short- term forecast modeling

• Interface to receive and process real- time and forecast meteorological data

• Link multiple models in a sequence for real-time simulation of , reservoir operation, river hydraulics, and flood impact analysis

7 | MIDH2O September 05, 2018 HEC-RTS Meteorological Data • Supports standard HEC models and can be extended to support other models and data processing tasks MFP Supplemental Program • Provides access to native model interfaces for data editing and display HMS • Deployed to over 35 USACE district and division offices * Flow

• UASCE version: Corps Water Management ResSim System (CWMS) Flow • CWMS is server based and uses Oracle Database. HEC-RTS is PC based and uses RAS HEC-DSS.

Custom Report Generator * http://www.hec.usace.army.mil/cwms/cwms.aspx

8 | MIDH2O September 05, 2018 Why HEC-RTS?

• Familiarity with HEC models

• Has an interface to receive and process real-time and forecast meteorological data

• Discrete models developed outside and then linked together in RTS

• Provides a platform to integrate different models • Rainfall-runoff model to predict peak (HEC- HMS) • Reservoir operation model to evaluate reservoir releases (HEC-ResSim) • Riverine hydraulics model to predict river stages (HEC- RAS)

9 | MIDH2O September 05, 2018 HEC-RTS GUI

10 | MIDH2O September 05, 2018 Data Acquisition and Data Visualization Modules

Source: Chan Modini, USACE‐HEC, Real‐Time Flow/Stage Forecasting, Inundation Mapping and Decision Support For the Russian River Basin with CWMS 3.0 / HEC‐RTS 3.0, MIDH2O Symposium, September 2017

11 | MIDH2O September 05, 2018 Data Acquisition and Data Visualization Modules

Source: Chan Modini, USACE‐HEC, Real‐Time Flow/Stage Forecasting, Inundation Mapping and Decision Support For the Russian River Basin with CWMS 3.0 / HEC‐RTS 3.0, MIDH2O Symposium, September 2017

12 | MIDH2O September 05, 2018 HEC-RTS GUI

13 | MIDH2O September 05, 2018 14 | MIDH2O September 05, 2018 Project Overview

• To provide a Real Time Decision Support System for the Merced Irrigation District • Water budget – Snow Accumulation, Snow Melt, Rainfall Runoff into Lake McClure • Irrigation Deliveries to the Turnouts • for the Merced Group • Power Generation Scheduling

15 | | MIDH2O September 05, 2018 MIDH2O Features

• Fully automated MIDH2O system • Data retrieval and QAQC • Generate Forecast • Post Results • Generate custom report

• Each forecast run has a three week simulation period – two weeks of lookback and 1 week of forecast

• Forecast simulation run at 6 o’clock and 12 o’clock PST

• HEC-HMS includes snowmelt modeling

• Integrated with MID’s WISKI database

• Scripts written to update initial soil moisture deficit values and transfer initial snowmelt grids

16 | MIDH2O September 05, 2018 Meteorological Model  Uncoupled Surface Layer (USL) model runs a NWP model that GFS Downscaling & NAM focuses entirely on near surface Bias Correction Hi-res HRRR Terrain data conditions NDFD Pre-processor SREF  Terrain elevation ranges from 52 Gridded to 13,090 ft MOS GDPS Clouds Weighted HIRESW Precipitation  Orographic effect, mountain Ensemble etc. shadow, temperature in north vs (WRF) south facing slopes Observations  Temperature High resolution (500 meter) USL Land surface Humidity hourly gridded precipitation and data Wind temperature grids “Tuning” (0-100m AGL) params  Accurate land surface properties and realistic near‐surface physics

Source: CustomWeather Forecasting Merced Irrigation District: The High Resolution Uncoupled Surface Layer (USL) Model, MIDH2O Symposium, September 2017

17 | MIDH2O September 05, 2018 Precipitation Runoff Model

• Computes streamflow throughout the Merced River watershed based on observed and forecast precipitation and temperature and watershed runoff characteristics • Includes snowmelt computations • Event-oriented model run continuously

18 | MIDH2O September 05, 2018 HEC-HMS Components

• Loss -> Deficit and Constant • Canopy -> Simple Canopy • -> Monthly Average • Moisture deficit can recover • Transform -> ModClark • Routing -> Modified Puls and Muskingum-Cunge • -> Recession

19 | MIDH2O September 05, 2018 Uncertainty in Real-Time Forecasting

• Inaccuracy in forecast precipitation and temperature • Is precipitation falling as or snow? • HEC-HMS uses one PX Temperature • Initial conditions • Soil moisture •SWE • Need professional judgment

20 | MIDH2O September 05, 2018 MIDH2O January 9, 2017 Event Forecast

MIDH2O Forecast: Merced River at Pohono Bridge January 9, 2017 Storm

2017.01.04‐0400 2017.01.04‐1000 2017.01.05‐0400 2017.01.05‐1000 2017.01.06‐1000 2017.01.07‐1000 2017.01.08‐1000 2017.01.09‐1000 OBSERVED

30,000

25,000

20,000

15,000 Flow (cfs)

10,000

5,000

0 03 Jan 17, 10:00 04 Jan 17, 10:00 05 Jan 17, 10:00 06 Jan 17, 10:00 07 Jan 17, 10:00 08 Jan 17, 10:00 09 Jan 17, 10:00 10 Jan 17, 10:00

21 | MIDH2O September 05, 2018 22 | MIDH2O September 05, 2018 HEC-ResSim Overview

 To model operations at reservoirs using different set of operational rules and constraints  Uses reservoir inflow and downstream local flows computed by HEC-HMS  Reservoir operation for Lake McClure, Lake McSwain, and Merced Falls Forebay to water delivery and power generation  Determine releases using operation sets and prescribed release schedules  Use mass-balance to determine pool elevation and storage for reservoirs

23 | MIDH2O September 05, 2018 HEC-RAS for MID

Unsteady-state hydraulic model of Merced River from the Exchequer Dam to San Joaquin River  New model development between Exchequer Dam and Cressey  Existing DWR’s model of Merced River between Cressey and San Joaquin River

Uses reservoir releases from HEC-ResSim and local inflows from HEC-HMS

Calibrate to available high water marks and gage record

Water quality modeling

Sediment transport modeling

24 | MIDH2O September 05, 2018 Custom Report

• 29 page report • Past, current, and estimated future conditions • Precipitation and snowpack • Reservoir status • Diversion demand • Forecasted flow at key downstream locations • Appendix includes: • Current NWS San Joaquin Report • 5-station precipitation index, snow water content (from CA DWR) • Merced Watershed Report • Historical SWE time series for Ostrander and Tenaya Lakes • Lake McClure current conditions and precipitation

25 | MIDH2O September 05, 2018 26 | MIDH2O September 05, 2018 Real-time and Planning Models

• Real-time • Flood and Conditional Space Operations • Downstream Flow Requirements • Demand and Power Management • Hourly Time Forecast for One Week • Planning • Snow Water Equivalent Analyses • April to July Snowmelt Flow Volume Forecast • Habitat Restoration • Fish Pulse Flows

27 | MIDH2O September 05, 2018 28 | MIDH2O September 05, 2018 Additional MIDH2O Benefits

• Climate Change Impact HEC‐HMS Analysis • – Ground water coupled model

• Power Generation and HEC‐ResSim Scheduling

• October Pulse Flows HEC‐RAS • Update gage rating table • Merced River Water quality and temperature modeling

29 | MIDH2O September 05, 2018 Conclusion

• Phase 1 went live on October 2016 • From day 1, significant benefits realized over legacy forecast methods • Improved lead time and flexibility in forecasts and operational alternatives • Residual benefits to other district operations through optimization, increased efficiency and increased collaboration

30 | MIDH2O September 05, 2018 Merced Irrigation District Hydrologic and Hydraulic Operations (MIDH2O) Model

Marco Bell Ted Cassidy Bibek Joshi Merced Irrigation District Dewberry Dewberry [email protected] [email protected] [email protected] 209‐354‐2857 916‐380‐3774 916‐380‐3772