Models as a Planning ToolIntegrated Hydrologic Model Features for SGMA Conjunctive-Use Analysis

Randall T. Hanson1 & Steffen Mehl21 One-Water Hydrologic, LLC (http://www.one-waterhydrologic.com/), RandyTHanson@gmail.com

2 California State University, Chico, smehl@csuchico.edu

Todays Update

• How has Conjunctive Use Influenced Us?

• New Integrated Hydrologic Model Features

• Adaptation/Sustainability

• SGMA Related Issues

This is all about Conjunctive UseCA-DWR: Conjunctive management or conjunctive use refers to the coordinated and planned use and management of both surface water and groundwater resources to maximize the availability and reliability of water supplies in a region to meet various management objectives.(https://water.ca.gov/-/media/DWR-Website/Web-Pages/Programs/California-Water-Plan/Docs/RMS/2016/08_ConjMgt_GW_Storage_July2016.pdf)

U.S. Bureau of Reclamation Definition: Conjunctive use is the coordinated use of surface water and groundwater (https://www.usbr.gov/library/glossary/#C).

UNESCO/IHP Definition: Combined use of surface water and groundwater to optimize the use of water resources.(https://en.unesco.org/themes/water-security/resources)USGS: NONE (https://water.usgs.gov/edu/dictionary.html)

Complete Definition: Combined use of precipitation, surface water, recycled, imported, and groundwater to optimize the use and quality of all water resources for all uses.

The elements of Conjunctive UseTypically Included in Hydrologic Assessments:GroundwaterSurface waterRainfallReservoir ReleasesTypically neglected in Hydrologic Assessments:Recycled waterFlood water (FLoodMAR)Imported waterInefficient Irrigation/Artificial RechargeSeawater intrusion is a (freshwater) storage loss (freshwater is replaced by seawater)Land Subsidence and Differential Land Subsidence (Earth fissures/Damaged Infrastructure)Completely neglected in Hydrologic Assessments:Wellbore FlowAquifer Storage and Recovery (Recharge Credits/Subsurface Storage)Drain ReturnflowsCaptured Runoff

Modeling Conjunctive Use with MF-OWHM2 All the Water, All the Time, Everywhere

Todays Update

• How has Conjunctive Use Influenced Us?

• New Integrated Hydrologic Model Features

• Adaptation/Sustainability

• SGMA Related Issues

MF-OWHM2 Conjunctive-Use Framework is Fusion/Update/Upgrades of MF-2005 Code Family

BCMBasin Characterization Model

Precipitation/PETRecharge/Runoff

PRISM Climate Data

GCMsGlobal Climate Models(LOCA Downscale/Bias)

SGMA GSP Models of Bull-118 GW SubBasin Plus Entire Watershed

(Modified from Boyce et al., 2020)

Download newest USGS MF-OWHM version 2.1.1 at:https://code.usgs.gov/modflow/mf-owhm

Additional MF-OWHM2 Features/Upgrades

New I/O Options New Solver Options New Flow Package Features (LPF, UPW) New Well Package Features New Conduit Flow Process New SFR and SWR Features New GHB Features New PVAL and MULT package Features & Linkages New SUB Package Features & Linkages (Deforming mesh) New HFB Features New HOB & HydMod Options New Model Information New Internal Math Capabilities Additional ET Features with RIP and FMP4 Additional Output Control Features New FMP4 Features (Budgets, Water Sources, Crop/Irrigation) Many New Budget(s) Features

Not Available in any other Modflow versions Developments driven by Conjunctive-Use Modeling

Plus Bug fixes not in other versions

Todays Update

• How has Conjunctive Use Influenced Us?

• New Integrated Hydrologic Model Features

• Adaptation/Sustainability

• SGMA Related Issues

MF-OWHM2 Model Constraints for Adaptation & Sustainability Analysis ADAPTATION ANALYSIS

SUSTAINABILITY ANALYSIS

Changing & Fractional Land Use/Ownership (FMP4) Changing Irrigation practices (FMP4) Redirected Recharge or Supplies/Deliveries (FMP4/SFR/SWR/DRT/SWO) Reduced Salinity Loads (FMP4) Riparian Salvage (FMP4/RIP) Changing Well Ordinances (MNW2/FMP4) Climate Change and Drought Contingencies (Deficit Irrig., GW/SW Allotments-FMP4)

Surface-Water Constraints to reduce deliveries (Surface-water Allotments - FMP4) Groundwater Constraints to reduce pumpage (Groundwater Allotments, Pump Capacities - FMP4/MNW2) Recycled or Drain water Reuse (NRD Wellfield Option-FMP4, DRT return to SFR, ASR’s/Water Banks – FMP4) Deficit Irrigation for Climate Change/Variability or as a Management Strategy (FMP4/SWO/SFR)

1 Reduced ET--Elimination of Invasive Species

Adaptation/Sustainability Analysis with MF-OWHM2

2 Enhanced Wet-Period Recharge - FloodMar

3 Retire Ag Land or test other land uses/Irrigation Methods

4 Aquifer Storage-and Recovery Systems

5 Modify portions of water sources to reduce Salinity Load & Leaching or impact on Surface-water flows

6 Non-Routed Deliveries for Water Transfers or Reduced Demands

7 Constrain deliveries & leakage from rivers, canals, & drains

8 Evaluate Wellbore Flow and Constrain Pumpage/Screens9 Capture of Runoff and Drain

Return Flows for Reuse or Recharge

10Evaluate delayed Recharge, rejected Infiltration, Water Quality, & Tile Drains

Todays Update

• How has Conjunctive Use Influenced Us?

• New Integrated Hydrologic Model Features

• Adaptation/Sustainability

• SGMA Related Issues Require Modeling/Monitoring

MF-OWHM2-Ancillary IssuesGDE’s FMP/RIP/Drain Return flow to SFR

Fractional Land Use, Variable Stage-WdithDischarge, & Separate Floodplain land-surface elevations

Baseflow & Streamflow Capture (recharge/discharge) SFR/SWR/FMP-SWO: Dynamic Stage-Width-Flow relations, Tightly-coupled Reservoir Operations Generate releases that overcome changing conveyance to meet demands/deliveriesReturn flows from Diversions & Drain Flows (keep water in model)

Groundwater

Diversion/Conveyance

Drainage ReturnFlow

Seepage

Well

CropWaterUse

IrrigationCanal

Field Drain Rio Grande

Example of Conjunctive Use Linkages: Reservoir releases to diversion hydrology altered surface-

water reuse by groundwater pumping in New Mexico

One-Water GW/SW FeedbacksBigger picture includes two-way feedbacks within Demand-Driven and Supply-Constrained Coupling

Surface WaterStorage / Allocation

Release / Delivery/Allotments

GroundwaterAllotments / Right

Pumping Rates

Landscape Consumptive

Water Demand

Diversion

Pumping

Stream Flow

Aquifer Storage

GW DischargeGW Head

SW HeadSW Seepage

MF-OWHM2-Ancillary Issues

On-Farm Storage/Delayed Water Use FMP4-NRDs/UZF/SWOOn Farm Storage used for delayed irrigation for days – months for delayed irrigation, dust control, frost control, etc. Also used before crops are planted for pre-wetting and salinity flushing.

Fish Passage requirements SFR/FMP4/DRT/UZFFish passage modeling requires dynamic stream-channel attributes & modeling that keeps all water in the model until consumed and differentiates between wet and dry climate responses to flow plus channel width and stage

MF-OWHM2-Ancillary IssuesDrought Assessments Exempt from SGMA assessmentsClimate–based Scale Dependent features such as runoff, deep percolation, Crop Coefficients, Irrigation Efficiencies, Runoff Fractions of Applied water/Precip., and CanopyLong-term Climate Change Projections Needs to include inter-annual to inter-decadal & Multi-century variability along with climate changeModel needs to be able to assess climate linkages at different time scales: Operational (Seasonal to Multi-year)

Governance/Management (Seasonal to Inter-decadal)Capital Improvement (Inter-annual- Multi-century)

Regional Climate Cycles – Rio Conchos, Chihuahua, MexicoCasas Grande tree-ring index (733-2010 CE, 1,278yrs) & related climate and cultural events

Governance Issues 1944 Treaty of

the Rivers has 5-year delivery cycles.

8 Years is Average Dry-year period (15-year PDO MvAvgWindowof Tree Rings.

Dry Periods range from 12-41 years from Tree Rings.

(39 Years)

(20 Years)

Climate cycles are occurring on multiple time scales from inter-annual & Interdecadal to Multi-century with Droughts & Mega Droughts embedded in longer wetter and drier periods.(Renteria & Hanson, In Press)

NorCal Different Drought Response with some similar periods to SW climate

Climate Indices show similar phases & periods to Tree-ring indices

PDO

AMO

MF-OWHM2-Ancillary IssuesArtificial Recharge & Wellbore Flow

FMP4-ASRs (NRD Wellfield Option), MNW2 + FMP4/MNW2Assessment of Water-Quality Degradation

FMP4 Salinity Leaching Option, SFR, UZF, LAK Plus linkages to MODPATH/MODPATH-OBS & limited linkages to MT3D-USGS

Water Transfers Imports, Exports, & Intra-basinFMP4-ASRs (NRD Wellfield Option)/SWO Specified Deliveries

• GHB• FMP• SFR2• MNW2• UZF• SUB• HYD

Example Model: Pkgs/Processes

Salinity Leaching affects Water-Quality Degradation & Increased Demand for SW/GW Additional adverse SGMA Sustainability effect

Examples of MF-OWHM2 Budgets by Subregion, Water Source, & Crop Type

5

3

Increased Irrigation for Salinity-Leaching Demand by Farm (WBS)22-38% more irrigation for leaching at 99% Leaching depending on Crop types and water sources

Using Salinity-Leaching Option in FMP4 of USGS MF-OWHM2 (Boyce et al., 2020)

Urban area least Demand

GW-Only Farm 5 Biggest Demand

Increased Groundwater Pumpage for Salinity-Leaching Demand by Farm (WBS)

20-80% more groundwater pumpage for agricultural regions in growing season

Using Salinity-Leaching Option in FMP4 of USGS MF-OWHM2 (Boyce et al., 2020)

Largest change in GW use for Leaching is Farm 3

Increased Irrigation for Salinity-Leaching Demand by Crop & WBS (Farm)

22-43% (Vegetable Row Crops) & 24-34% (Orchards) additional irrigation for selected crops and farms

Using Salinity-Leaching Option in FMP4 of USGS MF-OWHM2 (Boyce et al., 2020)

Largest Leaching Demand is Vegetable Row Crops in Farms 1,2,& 3

SUMMARY & CONCLUSIONSMF-OWHM2 has features needed for SGMA, Fish Passage, Adaptation/Sustainability, &

Climate-Change/Variability Analysis Several Regulatory Issues overlap or extend SGMA requirements Droughts/Climate,

Environmental: Fish Passage/Habitat, Transboundary Aquifers, EPA Sole-Source Aquifers Several of the SGMA requirements such as groundwater degradation, land subsidence,

seawater intrusion, & water transfers are in need of additional analysis Linkages with other software such as the Basin Characterization Model (BCM) and

transport (MODPATH & MT3D-USGS) needs further development, fixes, and useUse of GCMs and Climate Variability (Sustainability in Droughts & Replenishment in Wet

periods) is needed in most areas & analysis beyond SGMA time periodsEntire Watersheds need to be analyzed for SGMA as land & water use extends past the

Bulletin-118 subregions with a combination of BCM & MF-OWHM2

Thanks and Any Questions??