april 10 – 13 henry b. gonzalez convention center san...
TRANSCRIPT
Texas Water 2012conference program
April 10 – 13 Henry B. Gonzalez Convention Center
San Antonio
2012 Conference Schedule....4-5Conference Highlights..........8-9Competitions........................24-25Exhibitor List..........................36-44 Facility Tours.................................58 Gloyna Breakfast........................19
Where to find...Guest Program............................58 Special Guests................................6 Host Committee.........................22 Maps..........................................27-29 Match the Name Game..........25 Presenter Contacts.............48-52
Quick Exhibitor Index.......31-34 Sponsors........................................26 TAWWA....................................56-57 Tech Sessions Schedule...12-19WEAT.........................................54-55
Water Conservation Utility Management & Workforce Issues Watershed Management Operator Forum
Demand Management Strategies for Tarrant
Regional Water DistrictBrian McDonald
Alan Plummer AssociatesMark Olson
Tarrant Regional Water District
Removing the Blinders: Using Dynamic Modeling to Promote
Financial SustainabilityJennifer Ivey
Red Oak ConsultingSkipper Shook
City of Fort Worth
Watershed Management To Address Nutrient and Sediment Issues
Paul JensenAtkins North America
Ka-Leung LeeAtkins North America
David BuzanAtkins North America
Field Testing Addresses Operations and
Budget ChallengesKathy Fretwell
Kennedy Jenks ConsultantsAurora Gonzales
Kennedy Jenks Consultants
9:30 - 10:00 am
Tools to Determine Water Savings – Engineering End-Use
Models vs. Dynamic Models: A Dallas Case Study
Fujiang WenDallas Water Utilities
Getting It Right: A Study of Cost of Service Wastewater
Treatment AllocationsSkipper Shook
City of Fort WorthJennifer Ivey
Red Oak Consulting
Engineering a Natural Solution to an Unnatural Challenge: Shoreline Stabilization and
Beautification on Lady Bird Lake Trail, Austin
Heather Harris CH2M HILL
Morgan ByarsCity of Austin
Comparing Solid State Water Meters to Positive
Displacement Meters in Residential Services
Craig HannahJohnson Controls
10:00 - 10:30 am
Untapped Potential: The Effectiveness of
Municipally-Driven ICI Water Audit Programs
Micah ReedCity of Fort Worth Water Department
Decision Making in the Face of Risk and Uncertainty
Jeffrey EdmondsURS Corporation
Evaluation Of Water Quality Models and Development of Example
EPDRiv1 and IWRS Models for San Antonio River
Sheeba Thomas San Antonio River Authority
Yu-Chun Su Atkins North America
Xin He Atkins North America
Ka-Leung Lee Atkins North America
Cost EffectiveAutomated Dead End Water Main Flushing
Aaron RussellCity of Burleson
10:30 - 11:00 am
When the Rain Stopped: Two Cities’ Pursuit of Water
During Historic Drought Conditions in Central Texas
Aaron ArcherHDR EngineeringKenneth WheelerCity of Cedar Park
Wayne WattsCity of Leander
Hiring Texas VeteransBryan Daye
Texas Veterans Commission
Effects of the 2011 Drought in Texas
Karl WintersU.S. Geological Survey
Gregory StantonU.S. Geological Survey
Water SupplyManagement Using
AMI TechnologyBernard Dunham
Delta Engineering Sales
11:00 - 11:30 am
North Texas Demonstrates Correlation Between Public Education and
Conservation BehaviorDenise Hickey
North Texas Municipal Water DistrictValerie Davis
EnviroMedia Social Marketing
Creating Your Own Workforce: City of Waco Partnership
for Water EducationTeresa BryantCity of Waco
Jonathon EcholsCity of Waco
Dynamic Water Quality Modeling in Support of a Watershed
Protection Plan for Bastrop Bayou in Brazoria County
Yu-Chun SuAtkins North America
Paul JensenAtkins North America
Ka-Leung LeeAtkins North America
Justin BowerHouston-Galveston Area Council
Operators and Engineers Working Together Provides
for Project SuccessJeff Sober
Carollo EngineersJohn Bennett
Trinity River Authority of Texas
11:30 am - N
oonTECHNICAL SESSIONS THURSDAY MORNING, APRIL 12
www.texas-water.com 15
ROOM 203-BModerators
Roger SchenkCDM Smith
ROOM 204-AModeratorsKatie McCain
Wachs Utility ServiceDean Sharp
Water Resources Management
ROOM 204-BModerators
Tom RayLockwood Andrews and Newnam
ROOM 101-A/BModeratorsSteve Fife
Baytown Water Authority
1
EVALUATION OF WATER QUALITY MODELS AND DEVELOPMENT OF EXAMPLE EPDRiv1 AND IWRS
MODELS FOR SAN ANTONIO RIVER
Yu-Chun Su, PhD,PE,CFM,CPSWQ,CPESC
Xin He, PhD
Ka-Leung Lee PhD PE CFM CPSWQKa-Leung Lee, PhD,PE,CFM,CPSWQ
Sheeba Thomas, PhD,PE,CFM
GoalsEvaluation and development of
dynamic water quality (WQ) models y q y ( )
Support Texas Instream Flows Program (TIFP)
WQ Model evaluation and comparison
2
WQ Model Evaluation Steady state or dynamic?
Storm event based or continuous simulation?
WQ constituents of interest?
Temporal resolution?
Spatial resolution?
Public domain? Public domain?
Potential applications:
TIFP, WQ Standards, CRP, TMDL, 303(d), MS4, BMP
evaluation, monitoring plans, etc.
WQ Models Evaluated EPDRiv1
HSPF
SWAT SWAT
QUAL-TX
WASP
CE-QUAL-W2
QUAL-2K
SWMM
DHI's MIKE programs
IWRS
HEC-RAS
3
Study Area
EPDRIV1 Background Dynamic 1D Hydrodynamic and WQ stream/river
model (not including watershed modeling)
Based upon CE-QUAL-RIV1 by USACE.
Developed by Lloyd Chris Wilson, Wilson
Engineering
Sponsored by Roy Burke III, Georgia EPDp y y , g
Funded by US EPA, Region IV
Riv1H and Riv1Q by Robert Olson, NRE, Inc.
4
About EPDRIV1 UI
EPDRIV1 Setup
Hydrodynamic Input File
WQ I t Fil WQ Input File
Lateral Inflows
Withdrawals/Diversions
Cross Sections Cross Sections
Boundary Conditions
Meteorological
5
EPDRIV1 Setup
EPDRIV1 Hydrodynamic Input
6
EPDRIV1 Variable Time Steps
EPDRIV1 Lateral Inflow
7
EPDRIV1 WQ Constituents
EPDRIV1 WQ Parameters
8
EPDRIV1 WQ Parameters at XS
EPDRIV1 Model Runs
Run A – Steady State, Q = 485 cfsy ,
Run B – Steady State, Q = 95 cfs
Run C – Dynamic, 7/1-31/09
Run D Dynamic 8/1/08 9/30/08Run D – Dynamic, 8/1/08 – 9/30/08
Run E – Dynamic, 1/1/05 – 12/31/09
9
Run A Results – DO
5.8
6.0
QUAL‐TX EPDRIV1
4.6
4.8
5.0
5.2
5.4
5.6
DO (m
g/L)
4.0
4.2
4.4
4.6
010203040506070
River Mile
Run A Results – NH3-N
1.4
QUAL‐TX EPDRIV1
0 4
0.6
0.8
1.0
1.2
NH3‐
N (m
g/L)
0.0
0.2
0.4
010203040506070
River Mile
10
Run B Results – DO Longitudinal
9
Run B DO Calibration ‐ Longitudinal Profile
Model 7/14/2009 11:15 Model 7/14/2009 14:00 Observed
3
4
5
6
7
8
DO (m
g/L)
0
1
2
010203040506070
River Mile
Run C Results – DO Longitudinal
9
Run C DO Calibration ‐ Longitudinal Profile
Model 7/14/2009 11:15 Model 7/14/2009 14:00 Observed
3
4
5
6
7
8
DO (m
g/L)
0
1
2
3
010203040506070
River Mile
11
Run D Results – DO Longitudinal
7
8
Run D DO Calibration ‐ Longitudinal Profile
Model 8/6/2008 Observed
0
1
2
3
4
5
6
010203040506070
DO (m
g/L)
River Mile
3
4
5
6
7
8
9
DO (m
g/L)
Run D DO Calibration ‐ Longitudinal Profile
Model 9/16/2008 Observed
7
8
Run D DO Calibration ‐ Longitudinal Profile
Model 9/3/2008 Observed
0
1
2
010203040506070
River Mile
0
1
2
3
4
5
6
010203040506070DO
(mg/
L)River Mile
Run E Results – TemporalStation ID: XSECT 1-242
35000
40000
35
40
NH
3 (
mg/
L)
10000
15000
20000
25000
30000
35000
Flow
(cf
s)
10
15
20
25
30
35
D1
(m
g/L)
; Nor
gan (
mg/
L); N
01/01/2004 01/01/2005 01/01/2006 01/01/2007 01/01/2008 01/01/2009 01/01/2010 01/01/2011
Date
0
5000
0
5
deg
C);
DO
(m
g/L)
; CB
OD
Nitrate at XSECT 1-242 NH3 at XSECT 1-242 Norgan at XSECT 1-242CBOD1 at XSECT 1-242 DO at XSECT 1-242 Temp at XSECT 1-242Flow at XSECT 1-242
12
Run E Results – Flow
Run E Flow Calibration ‐ XSECT 1‐242
Observed Model
15000
20000
25000
30000
35000
Flow
(cfs)
0
5000
10000
1/1/05 1/1/06 1/1/07 1/1/08 1/1/09 1/1/10
Run E Results – Temperature Temporal
35
Run E Temperature Calibration ‐ XSECT 1‐242
Model Observed
15
20
25
30
35
mper
ature (d
ec C)
0
5
10
1/1/05 1/1/06 1/1/07 1/1/08 1/1/09 1/1/10
Tem
13
Run E Results – DO Temporal
14
Run E DO Calibration ‐ XSECT 1‐242
Model Observed
6
8
10
12
DO (m
g/L)
0
2
4
1/1/05 1/1/06 1/1/07 1/1/08 1/1/09 1/1/10
Run E Results – NH3 Temporal
0 6
Run E NH3‐N Calibration ‐ XSECT 1‐242
Model Observed
0.3
0.4
0.5
0.6
NH3‐N
(mg/L
)
0
0.1
0.2
1/1/05 1/1/06 1/1/07 1/1/08 1/1/09 1/1/10
14
Run E Results – NO3 Temporal
Run E NO23‐N Calibration ‐ XSECT 1‐242
Model Observed
8
10
12
14
16
18
NO23
‐N (m
g/L)
0
2
4
6
1/1/05 1/1/06 1/1/07 1/1/08 1/1/09 1/1/10
N
Run E Results – OrgN Temporal
1.8
Run E Org‐N Calibration ‐ XSECT 1‐242
Model Observed
0.8
1
1.2
1.4
1.6
1.8
Org‐N
(mg/
L)
0
0.2
0.4
0.6
1/1/05 1/1/06 1/1/07 1/1/08 1/1/09 1/1/10
15
EPDRIV1 Modeling Findings EPDRIV1 generates reasonable results
Provide a good option for WQ modeling
Powerful pre- and post-processors
Freeware – downloadable from www.epdsoftware.com
Substantial input data requirements
Required skilled/trained users Required skilled/trained users
Model stability could be an issue
Computation time can be extensive
Revised User’s Manual in the making
INFOWORKS RS
16
• Proprietary softwareD l d b W lli f d S ft
IWRS Background
• Developed by Wallingford Software, originally a British government organization
• Merged with MWH Soft in September 2009B I S ft i 2010• Became Innovyze Software in 2010
• Hydrodynamic and water quality modeling capabilities
• Network file
IWRS Setup
• Event file• Water Quality Module• Flows• Boundary conditions• Run Group
17
IWRS Main Window
IWRS Model Runs
Run A – Steady State, Q = 485 cfsRun A Steady State, Q 485 cfs
Run B – Steady State, Q = 95 cfs
Run C – Dynamic, 7/1-31/09
R D D i 8/1/08 9/30/08Run D – Dynamic, 8/1/08 – 9/30/08
Run E – Dynamic, 1/1/05 – 12/31/08
18
Run A Results – DORun A DO
QUAL‐TX EPDRIV1 IWRS
4 8
5
5.2
5.4
5.6
5.8
6
DO (m
g/L)
4
4.2
4.4
4.6
4.8
010203040506070
River Mile
Run A Results – NH3-N
1.4
Run A NH3‐NQUAL‐TX EPDRIV1 IWRS
0.6
0.8
1
1.2
NH3
‐N (m
g/L)
0
0.2
0.4
010203040506070
River Mile
19
Run B Results – DO Longitudinal
Run C Results – DO Longitudinal
20
Run D Results – DO Longitudinal
Run E Results – Flow
60000
model observed
20000
30000
40000
50000
Flow (cfs)
0
10000
20000
12/29/2004 7/17/2005 2/2/2006 8/21/2006 3/9/2007 9/25/2007 4/12/2008 10/29/2008
21
Run E Results – Temperature Temporal
Run E Results – DO Temporal
22
Run E Results – NH3 Temporal
Run E Results – OrgN Temporal
23
Additional IWRS Modeling Findings
Easier pre-processing than EPDRiv1
Unable to directly import and use meteorological data
Limitation on DO modeling methodologies
EPDRiv1 and IWRS Model Comparison
EPDRiv1 IWRS
SourceEPA
Georgia EPD Wallingford Software (Innovyze)
C t P bli D i P i tCost Public Domain Proprietary
Pre-Processor Powerful Powerful
Post-Processor Powerful Powerful
Accuracy High High
User Skill Level Highly-trained users only Highly-trained users only
Ease of Use Easy with trained users Easy with trained users
Good for typical runs
Computation Time
Good for typical runsLong when having many XS, small
time step and long-term runs Limited long-term runs
Model StabilityMedium - Depends on XS spacing
and time stepsMedium - Depends on XS spacing
and time steps
User's ManualMedium
New version to be released soon Medium
1
EVALUATION OF WATER QUALITY MODELS AND DEVELOPMENT OF EXAMPLE EPDRIV1 AND IWRS MODELS FOR SAN ANTONIO RIVER
Sheeba Thomas, San Antonio River Authority
600 E. Euclid, San Antonio, Texas 78212
Yu-Chu Su, Xin He, and Ka-Leung Lee; Atkins North America
ABSTRACT
This paper provides a summary of the evaluation and development of dynamic water quality (WQ) models that can be used to support the Texas Instream Flows Program (TIFP). Two separate yet parallel modeling efforts were conducted for the San Antonio River (SAR) in Bexar, Wilson, and Karnes Counties. The first effort was sponsored by the Texas Commission on Environmental Quality (TCEQ) to evaluate and develop WASP, QUAL2K, and HEC-RAS models. The second effort was sponsored by the San Antonio River Authority (SARA) and conducted jointly by SARA and Atkins that involved the evaluation of suitable WQ models, and the development of two example models, the Georgia Environmental Protection Department Riv1 (EPDRiv1) and InfoWorks RS (IWRS) models, using the same reach of SAR as the TCEQ effort. The modeling efforts focused on the conventional WQ constituents as required by the instream flow studies. The purpose of the efforts was to evaluate dynamic WQ models including the type of input data required, ease of model setup, resolution, potential for application in instream flow studies, ability to model physical-chemical conditions, prediction of constituent loadings as well as capabilities and limitations of the models. This paper also provides a summary of the EPDRiv1 and IWRS model development and calibration efforts, example model runs, and their results. The study reach of this effort was on the SAR from near the confluence with Medina River in Bexar County to the Falls City gage in Karnes County. This study area is of special interest as it lies downstream of highly urbanized Bexar County and receives reclaimed water return flows from San Antonio in addition to it being a portion of the SAR where a Senate Bill 2 Instream flows study was conducted. The WQ model evaluation included the following major candidates: EPDRiv1, HSPF, SWAT, QUAL-TX, WASP, CE-QUAL-W2, QUAL-2K, SWMM, DHI's MIKE programs, and IWRS. The model evaluation and the development of example EPDRiv1 and IWRS models provided solid recommendations and tools to SARA for managing watershed water quality and help address TIFP issues and goals. KEYWORDS TIFP, Water Quality Models, Continuous Simulation, Hydrodynamic, EPDRiv1, IWRS
2
INTRODUCTION The Texas Instream Flows Program (TIFP) was established by Senate Bill 2 (SB2) in 2001 and is administered by Texas Commission on Environmental Quality (TCEQ), Texas Parks and Wildlife Department (TPWD), and Texas Water Development Board (TWDB). TIFP’s goal is to establish flow conditions in the rivers required for sound ecological health through a multidisciplinary study approach. The study disciplines include hydrology and hydraulics (H&H), biology, geomorphology and water quality (TWDB, 2008). As a result of which, this project, sponsored by the San Antonio River Authority (SARA) and conducted jointly by SARA and Atkins, was conducted for the San Antonio River (SAR) in Bexar, Wilson, and Karnes Counties to understand the effect of varying flow conditions by use of numeric models. Another parallel effort, under separate sponsorship by TCEQ, developed WASP, QUAL2K, and HEC-RAS models by other consultants for the same reach of SAR. A water quality workgroup was developed that consisted of TCEQ, TWDB, SARA, TPWD and supporting consultants. The following WQ model requirements were identified by the TIFP WQ modeling workgroup:
Ability to model WQ constituents [dissolved oxygen (DO) and temperature at a minimum] under a range of flow conditions at control points or study sites along a river basin. Nutrients, turbidity, and salinity are also of interest to the TIFP.
Applicability of the model in multiple river basins in Texas with data inputs from individual basins.
One/multi-dimensional model integrating hydrologic data from the U.S. Geological Survey (USGS) gaging station control points and WQ data.
Ability to model daily Mean, Max, and Min temperature and dissolved oxygen. Possibly using an hourly time step.
Spatial resolution surrounding multiple control points or study sites along each river basin.
Ability to incorporate nutrient, turbidity, and salinity into the model. Ability to model the physiochemical conditions.
STUDY AREA The study reach of this project was on the SAR from near the confluence with Medina River to the USGS’ Falls City gauge in Karnes County, as shown in Figure 1. This study area is of special interest as it lies downstream of highly urbanized Bexar County and receives wastewater effluents from the largest wastewater treatment plants (Dos Rios wastewater treatment plant) in San Antonio in addition to its constituting a portion of the San Antonio River Instream flows Study area.
3
Figure 1 - Study Reach of San Antonio River
4
EVALUATION OF WATER QUALITY MODELS A variety of WQ models were evaluated, which included Water Quality Analysis Simulation Program (WASP), Hydrologic Simulation Software Program (HSPF), Soil and Water Assessment Tool (SWAT), Storm Water Management Model (SWMM), CE-QUAL-W2, Georgia Environmental Protection Division’s EPDRiv1, QUAL-TX/QUAL2E, QUAL2K, MIKE11, MIKE21, MIKE3, RMA2, RMA4, RMA10, Infoworks RS (IWRS), and others. Among these models, EPDRiv1 and MIKE11 are one-dimensional (1-D) hydrodynamic and WQ models, RMA 10 and MIKE 3 are 3-D hydrodynamic models, and IWRS, MIKE21, and RMA2/RMA4 have the capability of modeling in 2-D. These models' abilities to conduct the needed water quality simulations in support of the study needs were evaluated and summarized in this report. The evaluation also considered the ease and cost of model development and calibration (including the availability of existing models) and compatibility with GIS interfaces. The selection of WQ modeling software and GIS interfaces depends greatly on the needs or goals of the modeling effort; i.e., suitable models should be selected so that the needs/goals can be achieved. For the TIFP, the selected WQ models need to be able to conduct continuous simulation of the constituent fate and transport through both dry- and wet-weather conditions. In addition, given the various applications of different types of models to various types of water bodies and watershed characteristics, more than one type of WQ models may be needed for comprehensive demonstration of water quality conditions in streams. For watershed modeling, a dynamic watershed model such as HSPF, SWAT, or SWMM would be needed to provide runoff and constituent loading input to instream models, which may include QUAL-TX, EPDRiv1, IWFS, WASP, and other models. Given that the existing QUAL-TX models have been approved by EPA and TCEQ for wasteload allocation purpose, the replacement of these models by EPDRiv1, IWFS, or other dynamic models will require approval by the regulatory agencies. Sources of evaluation information include the review of models by Ward and Benaman (1999), publications by Water Environment Research Foundation (WERF, 2001, 2003) and user's manuals from various models. In-depth details of the model evaluations are included in SARA and Atkins (2010). Based on the evaluation of model capabilities and limitations, HSPF, SWMM, and SWAT were found to be the main candidate models for watershed WQ modeling and EPDRiv1, IWRS, WASP, and QUAL-TX appeared to be the main candidate stream WQ models. COLLECTION AND REVIEW OF EXISTING DATA AND MODELS Available data that could support SAR model development were collected and evaluated. The reviewed data sets included stream cross-sections, topographic data, subwatershed delineations, soils, landuse and land cover, water use, water rights, permitted wastewater outfalls, TCEQ SWQM, 303d impaired water body, recently developed Bexar County DFIRM (Digital Flood Insurance Rate Map) data, EPA STORET data, and aerial imagery. Existing and available H&H and WQ models were also collected and reviewed that included Hydrologic Engineering Centers River Analysis System (HEC-RAS), Hydrologic Engineering Centers Hydrologic Modeling System (HEC-HMS), HSPF, QUAL-TX, SWAT, and SWMM.
5
These models were developed in the San Antonio River Basin by various local, state and federal organizations including SARA, City of San Antonio, TCEQ, USGS, TWDB, etc.
Given the WQ modeling needs for the instream flows study, the water quality workgroup decided that both watershed and riverine models be used in conjunction to better account for watershed loadings and instream dynamics of the fate and transport of constituents. HSPF was selected as the watershed model and it was decided to evaluate two instream water quality models, EPDRiv1 and IWRS. The watershed loadings of flows and constituents (HSPF output) as well as other included point sources were provided to SARA by the workgroup.
SETUP AND RESULTS OF INSTREAM MODELS
EPDRiv1 The EPDRiv1 model is based upon the CE-QUAL-RIV1 model developed by the U.S. Army Engineers Waterways Experiment Station (WES, now ERDC). The modifications to CE-QUAL-RIV1 to create EPDRiv1 were conducted by the Georgia Environmental Protection Division (EPD) of the Georgia Department of Natural Resources and the U.S. Environmental Protection Agency (EPA). As described in the user's manual (Georgia EPD, 2002), EPDRiv1 is a one-dimensional (longitudinal) hydrodynamic and water quality model. It consists of two major components: hydrodynamic and WQ. Each of these components is a separate computer program, with RIV1H being the hydrodynamic program and the RIV1Q being the WQ program. The hydrodynamic model component is typically executed first, and its output is saved to a file that is read by the WQ model component.
The EPDRiv1H program can simulate flows, water depths, flow velocities, water surface elevations, and other hydraulic characteristics along a studied stream. The hydrodynamic model solves the St. Venant equations as the governing equations using the widely accepted four-point implicit finite-difference numerical scheme.
EPDRiv1 can simulate the interactions of 16 state variables (Georgia EPD, 2002), including water temperature, nitrogen species (or nitrogenous biochemical oxygen demand), phosphorus species, dissolved oxygen, carbonaceous oxygen demand (two types), algae, iron, manganese, coliform bacteria and two arbitrary constituents. In addition, the model can simulate the impacts of macrophytes on dissolved oxygen and nutrient cycling. The model was designed for the simulation of dynamic conditions in rivers and streams.
EPDRiv1 can simulate streams with multiple tributaries. It can also simulate in-stream hydraulic control structures such as run-of-the-river dams, waterway locks and dams, and regulation dams. Reaeration due to flowing over dams can also be simulated. The model can accept time-varying hydraulic and WQ boundary conditions. For the hydrodynamic model, the boundary conditions can be either flows or stages at the upstream boundary, or flows stages or a rating curve at the downstream boundary. For WQ, constituent concentrations can be provided as boundary conditions. The model can also simulate point and non-point flows and constituent
6
concentrations/loadings as lateral inflows. It can also simulate the withdrawals or diversions by allowing user-specified diversion locations and time-series of withdrawal rates.
The EPDRiv1 model does not simulate sediment transport processes such as scour or deposition. The model also does not simulate the processes in the sediments that impact oxygen demand and nutrient release rates, which are instead input to the model
EPDRiv1 Model Setup
Using HEC-RAS models, developed previously, and model parameters by the water quality workgroup, EPDRiv1 models were developed for SAR. The developed models included the following major components:
Hydrodynamic Input File Water Quality Input File Lateral Inflow Files Cross-Sections Boundary Conditions Meteorological Data
To evaluate model performance, the following scenarios were developed by the workgroup and EPDRiv1 models were set up to match them in order to allow direct comparison of model results with the parallel modeling efforts undertaken by TCEQ:
Run A – Steady State Simulation, Q = 485 cubic feet per second (cfs) Run B – Steady State Simulation, Q = 95 cfs Run C – Dynamic Simulation for 7/1-31/09 Run D – Dynamic Simulation for 8/1/08 – 9/31/08 Run E – Dynamic Simulation for 1/1/05 – 12/31/09
Among the five scenarios, Run A was to test the ability of the model to conduct steady-state simulation using the same input as the TCEQ's QUAL-TX model under fully permitted conditions. Run B was to simulate a steady-state, low-flow condition using a self-reporting wastewater flow data from July 2009. Run C was the same as Run B except that it was a fully dynamic simulation using flow data from July 2009. Run D was to simulate a single pulse event using dynamic data from 8/1/2008 to 9/31/2008. Run E was to conduct a continuous long-term dynamic simulation using data from 1/1/2005 to 12/31/2009. Each modeling scenario requires a hydrodynamic input file with channel cross-section data such as initial water depth, downstream distance, roughness coefficients, and channel geometry including flowline elevation, all of which were imported from existing HEC-RAS models. Also needed were lateral inflows for the contributing sub-basins, which were extracted from the HSPF model, and point sources, i.e. wastewater effluents, which were provided by the workgroup.
7
Water quality input file contains kinetic coefficients and other parameters for water quality simulation. For the SAR model, water temperature, CBOD, organic, ammonia (NH3-N), and nitrate nitrogen (NO3-N), and DO were selected as the target constituents. Boundary conditions (upstream and downstream) were developed for each EPDRiv1 modeling scenario. Each file included both hydrodynamic and WQ time series at the boundary locations of the model. For upstream flow boundary, time series from the USGS Gage 08181800 at Elmendorf were used. For the downstream boundary, the Karnes County HEC-RAS model was executed to obtain the flow and water depth rating relationship for the most downstream cross-section of the EPDRiv1 model. Using the rating relationship and the USGS flow time series, water depth time series were developed and used as downstream boundary condition for the EPDRiv1 model. As for the WQ time series boundary conditions, data provided by the workgroup were used to ensure identical values and allow direct comparison of model results. EPDRiv1 Modeling Results The following figures show some of the results of the different modeled scenarios. Figures 2 and 3 show the comparison of EPDRiv1 simulated results (“EPDRiv1”) with model outputs from QUAL-TX for both DO and NH3-N. Figures 4 to 9 show simulated results (“Model”) when compared to observed data (“Observed”). Additional details on all the simulated parameters can be found in SARA and Atkins (2010).
Figure 2 - EPDRiv1 Run A DO Results
4.0
4.2
4.4
4.6
4.8
5.0
5.2
5.4
5.6
5.8
6.0
010203040506070
DO (m
g/L)
River Mile
QUAL‐TX EPDRIV1
8
Figure 3 - EPDRiv1 Run A NH3-N Results
Figure 4 - EPDRiv1 Run B DO Longitudinal Results
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
010203040506070
NH3‐
N (m
g/L)
River Mile
QUAL‐TX EPDRIV1
0
1
2
3
4
5
6
7
8
9
010203040506070
DO (m
g/L)
River Mile
Run B DO Calibration ‐ Longitudinal Profile
Model 7/14/2009 11:15 Model 7/14/2009 14:00 Observed
9
Figure 5 - EPDRiv1 Run C DO Longitudinal Results
Figure 6 - EPDRiv1 Run D Flow Results
0
1
2
3
4
5
6
7
8
9
010203040506070
DO (m
g/L)
River Mile
Run C DO Calibration ‐ Longitudinal Profile
Model 7/14/2009 11:15 Model 7/14/2009 14:00 Observed
0
500
1000
1500
2000
2500
3000
3500
4000
8/1/08 8/11/08 8/21/08 8/31/08 9/10/08 9/20/08 9/30/08
Flow
(cfs)
Run D Flow Calibration ‐ XSECT 1‐242
Model Observed
10
Figure 7 - EPDRiv1 Run E Flow Results
Figure 8 - EPDRiv1 Run E Temperature Results
0
5000
10000
15000
20000
25000
30000
35000
1/1/05 1/1/06 1/1/07 1/1/08 1/1/09 1/1/10
Flow
(cfs)
Run E Flow Calibration ‐ XSECT 1‐242
Observed Model
0
5
10
15
20
25
30
35
1/1/05 1/1/06 1/1/07 1/1/08 1/1/09 1/1/10
Temp
eratu
re (d
ec C)
Run E Temperature Calibration ‐ XSECT 1‐242
Model Observed
11
Figure 9 - EPDRiv1 Run E DO Results
EPDRiv1 Model Findings
The EPDRiv1 results presented above indicate that EPDRiv1 is capable of conducting steady-state and long-term dynamic WQ simulations and generating reasonable results. Thus, EPDRiv1 would be a good option for TIFP WQ modeling. EPDRiv1 has powerful pre-processors to help prepare model input data files. It also has powerful post-processor to view, animate, and export model results. Given that it is a freeware in public domain and the software can be downloaded from the EPD website (www.epdsoftware.com), EPDRiv1 should be a very attractive option for TIFP WQ modeling. The model's ability to import HEC-RAS geometry files directly is a major advantage for streams that already have HEC-RAS models developed through other programs; e.g., floodplain management. One caution is that most HEC-RAS models were developed for flood condition simulations while WQ simulations focus a lot on dry-weather base flow conditions and smaller storm events. As a result, the resolution of the low-flow portion of HEC-RAS cross-sections can be important to EPDRiv1 modeling while it might be not so important in a HEC-RAS floodplain model. Therefore, close examination of low-flow channels in a HEC-RAS geometry file should be conducted prior to importation into EPDRiv1. On the other hand, EPDRiv1 has substantial input data requirements and it can be time-consuming and costly to development and calibrate an EPDRiv1 model. The model's complexity and its ability to conduct extended WQ simulations also make it a model that requires skilled/trained users to develop and operate.
0
2
4
6
8
10
12
14
1/1/05 1/1/06 1/1/07 1/1/08 1/1/09 1/1/10
DO (m
g/L)
Run E DO Calibration ‐ XSECT 1‐242
Model Observed
12
In addition, the complex numerical solution scheme implemented in EPDRiv1 code requires a good balance of spatial and temporal resolution in order to achieve model stability. When cross-sections are close together, then very small time step may be required in order to achieve EPDRiv1 model stability. This requirement not only results in a longer EPDRiv1 model development time before obtaining a stable and calibrated model, but also results in longer simulation run time due to the need for small time step. The longer run time can be an issue for long-term simulations. For example, Run E took more than 11 hours of physical runtime on a Dell Precision M6300 computer for a hydrodynamic run and more than 24 hours for a WQ run. Another disadvantage of EPDRiv1 is that it is still under development so it is subject to change and frequent updates to the code are being made by the developers. In fact, this project has helped debugged the code and triggered the release of several new versions throughout this project period. In addition, the current version of the EPDRiv1 user's manual is old and not very helpful in terms of teaching the users how to develop and use the model and associated pre- and post-processors. This should change soon with the new user's manual being prepared and reviewed and to be released soon with Version 2.0 of EPDRiv1.
IWRS
Wallingford Software developed InfoWorks in 1997. InfoWorks RS is one of the tools in the IWRS suite of programs for simulation of riverine flow, rainfall-runoff, water quality, and sediment erosion/deposition. IWRS combines the flow simulation engine with GIS functionality as well as database storage within a single environment. IWRS can conduct hydrodynamic simulations in both one-dimensional (1-D) and 2-D, but it can only simulate water quality in 1-D in the longitudinal direction. IWRS uses a software tool Conveyance Estimation System (CES) that helps the user estimate the conveyance of a channel. Conveyance is calculated using the depth-integrated Reynolds-Averaged Navier-Stokes (RANS) equations. More information on the flow calculation, uncertainty estimation etc., is described in the Help Manual integrated within the IWRS program (MWHSoft, 2010). IWRS's water quality simulation engine is separate from the hydraulic engine. Therefore, the hydraulic simulation has to be conducted for the channel prior to making a water quality run. Water quality computations involve solving the advection-diffusion equations using finite difference method. IWRS Model Setup
The setups of IWRS models were similar to EPDRiv1, except that there was no provision for inserting meteorological data. The modeling scenarios (Runs A-E) were the same as described above for EPDRiv1 models.
13
IWRS Model Results
The following figures show some of the results of the different modeled scenarios. More details on all the simulated parameters can be found in SARA and Atkins (2010). Figures 10-11 show the comparison of IWRS simulated results (“IWRS”) with model outputs from EPDRiv1 and QUAL-TX for both DO and NH3-N. Figures 12 to 17 show simulated results (“Model”) when compared to observed data (“Observed”).
Figure 10: IWRS Run A DO Results
4
4.2
4.4
4.6
4.8
5
5.2
5.4
5.6
5.8
6
010203040506070
DO (m
g/L)
River Mile
Run A DOQUAL‐TX EPDRIV1 IWRS
14
Figure 11: IWRS Run A NH3-N Results
Figure 12: IWRS Run B DO Longitudinal Profile
0
0.2
0.4
0.6
0.8
1
1.2
1.4
010203040506070
NH3
‐N (m
g/L)
River Mile
Run A NH3‐NQUAL‐TX EPDRIV1 IWRS
0
1
2
3
4
5
6
7
8
9
0102030405060
DO (m
g/L)
River mile
Run B DO ‐ Longitudinal Profile
Model at 7/14/09 11:00 Observed Model at 7/14/09 14:00
15
Figure 13: IWRS Run C DO Longitudinal Profile
Figure 14: IWRS Run D Flow Results
0
1
2
3
4
5
6
7
8
9
0102030405060
DO (m
g/L)
Run C DO ‐ Longitudinal Profile
Model at 7/14/09 11:00 Model at 7/14/09 14:00 Observed
River mile
0
500
1000
1500
2000
2500
3000
3500
4000
08/01/2008 08/15/2008 08/29/2008 09/12/2008 09/26/2008
Flow
(cfs
)
Run D Flow at XS‐242Model Observed
16
Figure 15: IWRS Run E Flow Results
Figure 16: IWRS Run E Temperature Results
0
5000
10000
15000
20000
25000
30000
35000
40000
12/29/2004 02/02/2006 03/09/2007 04/12/2008
Flow
(cfs
)
Run E Flow at XS 242Model Observed
0
5
10
15
20
25
30
35
12/29/2004 2/2/2006 3/9/2007 4/12/2008
Tem
pera
ture (°
C)
Run E Temperature at XS 242Observed Model
17
Figure 17: IWRS Run E DO Results
IWRS Model Findings
The IWRS modeling findings are based on the models' results, some of which are shown above, which reveal that IWRS is capable of conducting water quality simulations and can in general generate reasonable results.
IWRS has the capability of importing cross section data from other models such as HEC-RAS. The importation process maintains the integrity of the cross-sections with respect of the Manning's roughness values and the location of channel overbanks, which is a very helpful function to the user. It also has powerful pre- and post-processors. The data input steps are less laborious and intuitive and the user can use either English or SI Unit System. The program has powerful pre and post processors. Its powerful graphical user interface (GUI) helps create animated simulation results, user friendly tabulated results both in profile and cross-sectional views. IWRS can conduct continuous long-term simulation along stretches of rivers and creeks especially for the hydrodynamic component and even generate floodplain maps. The hydrodynamic simulation results matched very closely with the observed data
IWRS is proprietary software. Major limitations of the program for water quality simulation include: (1) Inability to artificially vary reaeration coefficients along the length of the channel, but the program includes the capability to add another reaeration coefficient that can be applied to structures such as weirs; (2) Inability to directly import and use meteorological data for water quality simulation. These limitations have been logged in to the developers for further improvement of IWRS.
0
2
4
6
8
10
12
12/29/2004 2/2/2006 3/9/2007 4/12/2008
DO (m
g/L)
Run E DO at XS 242Observed Model
18
Similar to EPDRiv1, IWRS is a complex program, has substantial data needs, and requires skilled or trained users to set up and conduct simulations. The users' manual is not very helpful in explaining the steps involved in IWRS modeling in sufficient detail. Multi-year simulation also can require substantial physical run-times, e.g. Run E took about 11 hours for the hydrodynamic component and 36 hours for the water quality simulation.
As a summary, IWRS has hydrology, hydraulics, and water quality engines and can model water quantity, quality, and sediments all in one program with some limitations depending on the needs of modeling. CONCLUSIONS The above described findings suggest that EPDRiv1 is a good option for instream flow WQ modeling and hence TIFP. Depending on the needs, resources, and available data of a particular stream, EPDRiv1 can be a very powerful tool to help address riverine water quality issues and goals. It can also be an overkill tool if a stream has minimal water quality analysis needs or resources to develop a complex model such as EPDRiv1. Similarly, IWRS is found to be an option capable of giving good results. However, IWRS has major limitations on WQ simulations, including high cost/fee and having limited options in setting up reaeration coefficients and not allowing user-specified meteorological data input. These limitations may affect the selection of IWRS as a tool for comprehensive water quality simulations. REFERENCES Georgia EPD. (2002) A Dynamic One-Dimensional Model of Hydrodynamics and Water Quality, EPDRiv1, Version 1.0, User's Manual. Draft 4/10/02.
MWHSoft. (2010) InfoWorks RS Help Manual, Version 11.0.
SARA and Atkins. (2010) Evaluation of Water Quality Models and Development of Example EPDRiv1 and IWRS Models for the San Antonio River.
Texas Water Development Board. (2008) Texas Instream Flow Studies: Technical Overview, Report 369.
Ward, G. H., Jr., and Benaman, J. (1999) Models for TMDL Application in Texas Watercourses: Screening and Model Review. CRWR Online Report 99-7.
Water Environment Research Foundation. (2001) Water Quality Models: A Survey and Assessment. Project 99-WSM-5.
Water Environment Research Foundation. (2003) WERF Model Selection Tool.