Master Planning and Hydraulic Modeling Shay Ralls Roalson, PE Saša Tomić, Ph.D., PE, BCEE Collection Systems Webinar WEAT Collections Committee May 15, 2013
Why Prepare a Master Plan? Identify existing capacity constraints in your system Identify growth areas and improvements needed to serve them A well-prepared master plan results in a CIP that Is validated Is defensible Uses a common cost basis
Data Collection WWTP flow records Lift station pumping records GIS or other mapping of existing system Existing land use, such as Low Density Residential High Density Residential Commercial Industrial Other (hospitals, university campuses, etc.) Flow monitoring Select locations to help quantify flow projections by land use
Master Planning Steps Determine existing system flows and geographic distribution WWTP and lift station records Dry and wet weather flow monitoring Establish planning horizon and develop growth projections Regional planning Land use planning Known development projects Develop a model of your system and load flow projections Use available information such as GIS Field verify where needed
Modeling Philosophy A successful modeling project delivers a tool that provides a continuous Return on Investment (ROI) To deliver the continued ROI, a model needs to be 1. Accurate and Applicable 2. Maintainable and Adaptable 3. Accepted and Used A hydraulic model can pay for itself the first time it is actually used by the Owner.
IMPORT -Rain gage data -Flow monitor data -Subcatchments EXPORT -RTK -Unique Subcatchment IDs -Subcatchment Polygons -Wastewater Loads -RDII (if different) -Area/Contributing Area -Land Use -Population -Wastewater Profile -Additional Flow (WW Profile Applies) -Trade Flow (TradeProfile Applies) -RTK Subcatchments -Parcel Data -Land Use/Zoning -Elevation/Contours -Basin Boundaries -Pipe Network -Water Billing Data -Wastewater Flow Data Scenario Parameters (e.g. days, duration)) -Unique Manhole ID (UID) -Coordinates -Rim Elevation -Ground Elevation -Width -Design -Bottom Elevation -Shelf Elevation -Type (e.g. stored, sealed) Nodes (e.g. manholes ) Infoworks Network -Utility GIS/CAD Data -As-Builts -Survey Data -In-house knowledge NOT CALIBRATED: ModifyNetwork and Components Based on Calibration Results -Unique Pipe ID -Manhole UIDs (Up/Down) -Material -Length -Inverts (Up/Down) -Diameter -Roughness Type and Coefficients Conduits (e.g. pipes) Project Rain Gage Data Infoworks Run Calibration Analyze Data -Storm Types (e.g. Observed, 2-Year, 10-Year) -Time series data -Manhole UID Rainfall Group National/State Rain Gage Data Flow Monitor Data Project Rain Gage Data Flow Monitor Data Wastewater Group (Patterns) -Diurnal Patterns Zoning and Land Use Data Trade Group (Patterns) Direct Inflow to Manholes Modeling Process 1. Goals Definition and Software Selection 2. Model Creation / Update 3. Model Calibration 4. Knowledge Transfer 5. Model Use DATA RAINFALL DERIVED INFLOW AND INFILTRATION (RDII) SSOAP WASTEWATER SYSTEM MODELING PROCESS USING INFOWORKS AND SSOAP PROCESSED DATA INFOWORKS MODEL VALIDATION & ANALYSIS CALIBRATED Apply modeling philosophy principals at every step of a modeling project.
Modeling Software Selection
Modeling Software Selection Questions to ask Project vs. owner software Complexity vs. accuracy Static vs. dynamic Design vs. analysis Things to remember Start with your needs Select the software that will serve you, not the project needs.
Modeling Software Selection Software Products C R I T E R I A R A T I N G S Software Ranking
Model Creation / Update Questions to ask All-mains vs. trunk-mains One-to-one correlation Data accuracy vs. model goals Things to remember Software tools Future model needs Model maintenance Model your system, not the asset database.
Model Creation / Update Traditional Approach GIS GIS-Update Approach GIS Hydraulic Model Hydraulic Model Data Cleanup Data Cleanup Model Calibration OK? NO YES Model Calibration Simulation and Model Use Simulation and Model Use Build the model so it can be maintained.
Model Calibration Questions to ask Flow variation Calibration goals Data quality Things to remember Calibration vs. validation Know when to stop Model QC Only through validation can we assert model accuracy.
Knowledge Transfer Questions to ask Who will do modeling? Who will use results? Software vs. model training What else can the model do? The best way to learn something is to do it.
Model Use Questions to ask Do I need modeling software? Can I use simpler version of the software? Things to remember Master planning Integrated approach Green infrastructure And many, many more The most expensive model is the one that is not used.
Alternative Approach Modeling results can be used without any modeling software.
From a Model to a Plan Execute existing and future conditions models Identify capacity constraints Evaluate potential solutions Coordinate with condition assessment Identify potential capacity improvements Parallel pipes Transferring flow between basins New WWTP(s) in high growth areas Lift station elimination
Recommended Improvements It s an iterative process! Look for solutions that work for the long-term Avoid stranded infrastructure wherever possible Utilize life cycle cost estimates to compare alternatives Compare apples to apples
Presenting the Plan A good master plan is a desktop reference Explain assumptions Summarize data from other sources Provide charts and graphs Put tables of data in the appendix Recommend improvements by planning year Present construction cost estimates No door stops!
Questions / Discussion Shay Ralls Roalson, PE HDR Engineering, Inc. 512-912-5106 shay.roalson@hdrinc.com Saša Tomić, Ph.D., PE, BCEE HDR Engineering, Inc. 212-545-5430 sasa.tomic@hdrinc.com