AUTOMATED WELL PERMITTING

Application for Arc Hydro Groundwater and MODFLOW Analyst

Overview

Calibrated regional model is imported to ArcGIS as a “baseline” model

Candidate wells are added to baseline model using well package.

Impact of new well (changes in streamflows, drawdown, etc.) is analyzed using the MODFLOW OBS process, and standard model outputs

Wells can be accepted or rejected and database is updated automatically

Prepare calibrated model Establish Flow Observations Import calibrated model into the ArcGIS Read solution files and set a model “baseline” to

which future runs will be compared

Model Preparation

The MODFLOW OBS process is used to compare baseline flow

with simulated flows.

Drain feature

Observation name

Observed value

Simulated value

Drain_Time1 100 99

Drain_Time2 120 119

Drain_Time3 125 126

Drain_Time4 130 130

Drain_Time5 130 129

Output heads are copied to starting heads to facilitate drawdown

calculations

Step 1: User applies for a new well (coordinates, pumping rate, screen elevations).

Create a new feature in the Well feature class

Candidate Well Analysis

New Well (HydroID = 1001)

Candidate Well Analysis

Step 2: Create new instances in the WEL table.

CellID represents MODFLOW i, j, k values

SourceID is the HydroID of the well feature

Custom tool that creates MODFLOW instances based on the location of the well and the screen elevations and finds the appropriate MODFLOW cell.

Candidate Well Analysis

Step 3: Export the new well data to the MODFLOW text file

Candidate Well Analysis

Step 4: Run MODFLOW simulation with candidate well Use OBS process to compute new flows and rivers,

drains, etc. Export drawdown file as part of solution.

Candidate Well Analysis

Step 5: Read solution and compare to “base” simulation

Generate appropriate reports to guide well approval/rejection.

There can be a number of different criteria for comparison:o Changes in flows (observed vs. simulated equivalents) at

key features.o Drawdown at key locations.o Drawdown mapso Capture zones (using MODPATH).

Case Study #1 - SRWMD

Permitting criteria based on impact

to streams, springs, etc.

Well Analysis Workflow

Create new well update well table export well package file run MODFLOW import solution

build map layers

Case Study #1 - SRWMD

Location of candidate

well

Drawdown resulting from well

Changes in flows to sources/sinks

Case Study #2 – Virginia DEQ

Virginia Coastal Plain Model (VCPM)

10-layer MODFLOW model used to analyze impacts of candidate wells

Criteria based on state law Potentiometric surface

cannot fall below a critical surface (80% drawdown)

Area of Impact defined by drawdown = 1 ft

Heads for layer 8

Well Permitting Workflow

Create new well update well table export well package file run MODFLOW import solution build drawdown map layer

AUTOMATED WELL PERMITTING DEMO

Arc Hydro Groundwater

Products

Area of Impact Cells Area of Impact Contour

GIS Products

GIS Products

For more information

Norm Jonesnjones@aquaveo.com

http://www.archydrogw.com (AHGW Wiki page)http://www.aquaveo.com/archydro (Info on tools)