Loading...
Item 4F-4G Attachement BM E M O R A N D U M TO: FROM: SUBJECT: April 21, 2023 Alison Ortowski, Assistant City Manager Rob Cohen, Director of Public Works Water Master Plan Modeling Recommendation REQUEST We respectfully recommend completing water system modeling prior to the adoption of the updated Water Master Plan, and request to enter into an agreement with Freese and Nichols for these services. Freese and Nichols provided an updated scope of work in April 2023, and we recommend proceeding with the revised scope, which includes project management and data collection, water demand projections for existing and future conditions, city-wide all-pipes water model rebuild and calibration, water system performance analysis, and water system CIP and master plan report. BACKGROUND As required by charter, the City of Southlake updates certain master plan documents every four years. In 2012 the City of Southlake engaged Neel-Schaffer/Cheatham & Associates to develop Master Plan Updates, including modeling and analysis to identify needed improvements for current and future capacity. In 2017, the City engaged Freese and Nichols in a water quality study that evaluated the demand, water age, and other factors that impact the quality of the water throughout the system. In 2021, Public Works and Planning & Development Services began preparations for a master plan update, and with that the evaluation of updated studies and modeling to inform plan recommendations. The following questions and information shaped the basis of the request and recommendation above: •What will modeling tell us that we don’t already know? At a fundamental level, modeling the water system will ensure that our system can meet the demand of both our residential and day-time population, enhance water quality, and ensure that our system meets fire suppression requirements. The modeling will also inform us to direct resources toward correcting issues with current capacity and building out our system to handle future capacity. Finally, there are items pertaining to AWIA and SB3 recommendations, as well as emergency preparedness/system redundancy in general, that have not yet been evaluated from a feasibility and modeling standpoint. Our current knowledge of the water system is largely based on the 2012 study that our engineering and operations teams have raised numerous concerns about the accuracy of. The concerns include the assumptions used (population and per capita water usage), lack Page 2 of flow verification and model calibration in the study, and exclusion of known operational issues. • Based on the issues raised, what needs to be further investigated? The following summarizes the major items requiring further investigation: o Updated assumptions and testing of system changes since 2012 to determine the necessity of remaining CIP projects, inform future CIP projects, as well as identify projects needed for future capacity that should be included in the impact fee 10- year CIP. o Address and test known operational issues, including evaluating the existing pressure plane delineation, conducting flow analysis, and field testing. o Evaluate the feasibility of emergency preparedness redundancy, improve system resiliency, and reduce risk. • Do we need to model the full system to answer our questions? Due to the interdependency of the elements of the water system, it must be studied as a full system and cannot be isolated by geographical or priority areas. However, in modeling the system we have options on elements to include/exclude to best fit the needs of the master plan. SCOPE & TIMELINE The proposed project scope is attached to this memo, and includes all needed elements to finalize the master plan. Additionally, this scope includes the addition of conduct source trace modeling, which was included in the AWIA recommendations. This model is needed to understand the impact if a contaminant was introduced to the water system from one of the City's ground or elevated water storage tanks. To model under this scope saves the City an estimated $80,000 - $90,000. The estimated time to complete the full modeling is an estimated 9 – 12 months. Due to timing, the department moved forward in Q4 of FY 2022 to engage Freese & Nichols to complete pressure testing of the system to capture readings during the peak season. FINANCIAL IMPACT The financial impact of this agreement is estimated at $202,400. Funding for this agreement is budgeted in the AWIA project of the Capital Improvements Program (CIP). Attachments: Scope of Work Guide, updated April 2023 CC: Daniel Cortez, Director of Economic Development & Tourism Dennis Killough, Director of Planning and Development Services Lauren LaNeave, Deputy Director of Public Works – Administration Page 1 of 5 City of Southlake Water Master Plan Update - Scope of Services DRAFT April 5, 2023 UPDATED Project Background: This project is an update to the City’s 2012 Water Master Plan in order to proactively plan for the future of the distribution system in the City of Southlake. The master plan process will update the future demand projections, update the hydraulic water model, and provide an updated Capital Improvements Plan. As the City approaches its ultimate buildout conditions, the Master Plan update will focus more on operational optimization, water quality measures, and long-term sustainability rather than growth or facility expansion drivers. FNI will compare proposed projects to projects in the 2012 Master Plan to determine if they are still needed or can be removed from the City’s long-term plan. BASIC SERVICES Task A. Project Management and Data Collection A.1 Administration: Perform general administration duties with the project, including progress meeting scheduling, general correspondence, office administration, and monthly invoicing. A.2 Project Kick-off Meeting: FNI will conduct a kick-off meeting with the City to discuss and solicit input for objectives and goals of the project. The team will also review project scope, schedule, communication, and present a data request memorandum. A.3 Document Control: FNI has established Document Control procedures to enable proper recordkeeping and retrieval. The Document Control procedures use a standardized electronic and paper file index, set up at the outset of the project. Protocols are observed for electronic and paper records, confidentiality and security, and proper distribution and retention. Documents will be assigned unique names and the filename and path included in the footer of each document. A.4 Monthly Progress Reports: A Monthly Status Report will be submitted, summarizing progress against specific tasks and scheduled tasks to be accomplished in the upcoming month; outlining upcoming key decisions which will require input from, or discussion with, City staff; and listing any problems or unresolved issues. A.5 Data Collection: FNI will compile information from the City including GIS files, as-built, work order data and preliminary design drawings for projects currently under design. FNI will review the data request memorandum with the City to determine what data and data format is available from the City. FNI will obtain input on customer complaints to determine areas of pressure concerns during summer and winter conditions. Task B. Water Demand Projections for Existing and Future Conditions B.1 Utilize Data from City to Update Existing Population and Commercial Development and Water Demands: FNI will geocode the water billing meter data. FNI will utilize existing water meters, water account data, aerial mapping, and planning data from the City to estimate existing population and commercial development and distribution throughout the water service area. FNI will review historical water demand to estimate existing average and peak water demand and allocate these needs throughout the system. Page 2 of 5 B.2 Utilize City-Provided Land Use Assumptions for Future Conditions: FNI will utilize the City’s Comprehensive Plan and other recent updates to document land use assumptions for residential and commercial growth for existing, 5-year, 10-year, and ultimate buildout conditions based on the delineated service areas. City staff will provide FNI with updated Future Land Use Assumptions through the buildout planning condition. B.3 Develop Water Demand Projections: FNI will use the land use assumptions, historical usage data and input from the City’s staff to develop water demands for existing, 5-year, 10-year and ultimate buildout conditions for residential and commercial land uses. FNI will develop the water demands utilizing per-capitas, peaking factors values comparable to those used for modeling and planning in other cities in the region, and in accordance with TCEQ guidelines. B.4 Meet with the City to Review the Updated Demand Projections: FNI will prepare for and conduct a meeting with City staff on the updated population and water demand projections. Task C. City-wide All Pipes Water Model Rebuild and Calibration C.1 Evaluate GIS for Completeness for Developing All-Pipes Water Model: FNI will analyze the most recent water GIS information and historical mapping data to determine additional attribute data needs or connectivity corrections needed for water model development. C.2 Conduct Modifications to GIS Data to Fix Connectivity Problems throughout Selected Water Lines: FNI will run node connection routines on all selected lines to be modeled and conduct adjustments to fix all connectivity problems. C.3 Develop Water System Model to Include All Pipes: FNI will update the water model using the Innovyze InfoWater software using the current GIS lines and as-built drawings of pumping, storage and control valve facilities. The all-pipes model will consist of all lines that are currently in the GIS plus recently constructed lines that may not appear in the GIS. C.4 Assign Attribute Data to Water Model Pipes and Nodes: FNI will assign GIS based IDs to all nodes and pipes in the hydraulic model based on GIS IDs to maintain a 1:1 relationship. Nodes will be attributed to provide data flagging for source reference. Nodes will also be assigned a point type, elevation, pressure plane, and installation year if available. Each pipe in the hydraulic model will be assigned a diameter, roughness coefficient, and pressure plane. Additional information will include, if available, installation year, and waterline material. C.5 Update Facilities Data in Model: FNI will update the water model to include most current facility information such as on-site piping configuration, pump curves, pumping rates, storage tank dimensions, and valve types/operating parameters. C.6 Update Diurnal Curves in Model: FNI will update the diurnal curve information for each model node in the hydraulic model. Curves include residential and non-residential curves, and large users for each pressure plane. C.7 Update Demand Distribution Based on Available Geocoding Billing Meter Data: FNI will assign and distribute water demands based on the latest round of geocoded billing meter data. FNI will utilize the data to assign demand for up to three different demand scenarios. Nodes will be Page 3 of 5 attributed to provide data flagging for future reference. C.8 Update Model Scenario Controls: FNI will replicate pump and valve controls for up to three demand scenarios to simulate operating conditions in the distribution system. FNI will use the existing GIS pressure plane value statuses to identify pipes to be closed acting as divider valves between pressure planes. C.9 Distribute Future Water Demands throughout the City in the Model: FNI will distribute the water demands for each planning period throughout City using the information developed in Task B. Identified large industrial and commercial demands will be distributed as point loads in the water system model. C.10 Conduct EPS Model Calibration: FNI will conduct a 24-hour extended period simulation model calibration by adjusting c-factors, peaking factors, diurnal curves, and demand distribution until modeling results match the field pressure measurements and pump/tank operation. FNI will provide comparison graphs and mapping to document model calibration results. Task D. Conduct Water System Performance Analysis for Existing and Future Conditions D.1 Perform Average Day EPS Modeling of Existing System: FNI will utilize SCADA data from typical average day demand system operation to develop an existing system average day EPS simulation. FNI will conduct EPS modeling of the existing water system for average day operating conditions to evaluate tank cycling, system pressures and deficiencies within the existing water system. D.2 Perform Maximum Day EPS Modeling of Existing System: FNI will utilize SCADA data from typical maximum day demand system operation to develop an existing system maximum day EPS simulation. This scenario will include the peak hour demand condition. FNI will conduct EPS modeling of the existing water system for maximum day operating conditions to evaluate tank cycling, system pressures, and deficiencies within the existing water system. D.3 Conduct Fire Flow Analysis for Existing System: FNI will utilize the existing water system model to conduct fire flow analysis under existing maximum day demands to identify areas with less than adequate fire flow capacity. A minimum fire flow of 1,000 gpm will be used for analysis. The City will provide fire flow requirements for customers with required fire flows greater than 2,000 gpm, where available. Mapping of available hydrant fire flows will be overlaid on the existing water system mapping. D.4 Evaluate TCEQ Capacity Requirements Compliance: FNI will evaluate the system by pressure plane for compliance with the TCEQ Chapter 290 water system capacity requirements. FNI will analyze production capacity, pumping capacity, elevated storage capacity, and total storage capacity by pressure plane to determine if any deficiencies exist. D.5 Evaluate Existing Pressure Plane Delineation: FNI will analyze existing pressure plane delineation based on modeling results, field testing data and water supply locations. Evaluate and recommend modifications to the existing pressure plane boundaries. FNI will present mapping showing proposed water system pressures throughout City under new pressure plane boundary alternatives vs. existing pressure plane delineation if boundary adjustments are recommended. Page 4 of 5 D.6 Meet with the City on Existing Distribution System Performance Analysis: FNI will develop mapping associated materials on the existing system analysis, including calibration results, system deficiencies, and fire flow results. FNI will meet with the City to discuss the results of the existing system evaluation and identify potential level of service targets. D.7 Develop Water System Improvement Alternatives for Future Conditions: FNI will develop the following future scenarios to identify water infrastructure needs: · Future water scenarios include: o 5-year maximum day + peak hour model o 10-year maximum day + peak hour model o Buildout average day model o Buildout maximum day + peak hour model FNI will utilize these models to simulate a number of system improvement alternatives to meet future planning periods. Water system facilities and lines will be sized to meet maximum day demands, peak hour demands and to provide adequate fire flows of at least 1,000 gpm under maximum day demand conditions. D.8 Perform Water Age Modeling for the Distribution System: FNI will conduct water age modeling for the distribution system for up to three different operational scenarios using the operational controls developed in the performance modeling. FNI will run the EPS water age model for adequate simulation duration to ensure a repeating pattern of water age. FNI will use the EPS model to investigate potential operational modifications to reduce water age in areas of concern. FNI will prepare large scale color-coded mapping showing the water age throughout the system. D.9 Conduct Source Trace Modeling: FNI will conduct source trace modeling for up to three operational scenarios to identify mixing zones within the distribution system. FNI will prepare large scale color-coded mapping showing the predicted mixing zones throughout the system. This task does not include any chemical or chlorine residual analysis. D.10 Utilize Water System Model to Evaluate System Reliability and TW King to Upper Pressure Plane Evaluation: FNI will utilize the water model with proposed improvements to determine system capacity for up to three outage scenarios and the specific scenario of infrastructure requirements to supply the Upper Pressure Plane from TW King for redundancy. FNI will evaluate the potential for additional wholesale supplier connections from neighboring utilities. FNI will present reliability modeling results to the City and adjust the proposed system improvements as needed to reduce the water system vulnerability from system outages. D.11 Meet with City to Review Future System Analysis Results: FNI will meet with City to review alternatives for future system improvements for the water system and proposed system improvements to meet future water needs. FNI will prepare mapping to identify the need for the improvements based on future system analysis results. Task E. Water System CIP and Master Plan Report E.1 Develop Draft Water Capital Improvement Plan (CIP) Costs, Phasing Plan and Mapping: FNI will develop a draft CIP for the water system to address existing deficiencies while planning for future buildout conditions. The developed projects will be compared to the 2012 Water Master Page 5 of 5 Plan CIP list to determine if modifications are needed to the existing CIP list. The CIP will include the scheduling of projects based upon water modeling requirements and reliability needs, and mapping showing project locations. The CIP will also incorporate the recommendations from the City’s Risk and Resiliency Assessment, where applicable. FNI will develop draft sets of improvements in 5-year, 10-year, and ultimate buildout periods. FNI will develop planning level costs for each proposed project. Costs will be in current year dollars and will include allowances for engineering design, surveying, and contingencies. E.2 Meet with the City to Discuss Draft Capital Improvement Plan: FNI will meet with the City to discuss the recommended water system improvements for 5-year, 10-year, and ultimate buildout planning periods. E.3 Revise CIP and Prepare Draft Water System Master Plan Update Report: FNI will revise the hydraulic modeling and CIP based upon the City’s comments and feedback and prepare a master plan report discussing field test results, assumptions, water demand projections and recommended capital improvement plans including phasing and costs of improvements. The report will include colored maps showing proposed system improvements as well as GIS digital copies. FNI will provide the City with three (3) copies of the draft report for review plus an electronic PDF copy. E.4 Finalize Water System Master Plan Update Report: FNI will conduct a comments review meeting with City staff and will finalize the Master Plan Report based on feedback received. FNI will provide the City with five (5) copies of the final report, and electronic PDF copy, and any requested modeling/GIS files. E.5 Public Involvement and Presentations: FNI will prepare for and attend up to four (4) public meetings with various stakeholder groups to review and discuss the results and recommendations of the Water Master Plan Update. Task Task Name Labor Cost Expense Cost Total Cost A Project Management and Data Collection $17,187 $1,144 $18,331 B Water Demand Projections for Existing and Future Conditions $17,233 $1,279 $18,511 C City-wide All Pipes Water Model Rebuild and Calibration $28,624 $1,833 $30,457 D Conduct Water System Performance Analysis for Existing and Future Conditions $73,827 $4,958 $78,785 E Water System CIP and Master Plan Report $49,993 $6,323 $56,317 $186,864 $15,537 $202,400 $186,864 $15,537 $202,400 Basic Services Total GRAND TOTAL City of Southlake Water Master Plan Update UPDATED 4/5/2023 Summary by Task DRAFT Basic Services A Project Management and Data Collection B Water Demand Projections for Existing and Future Conditions C City-wide All Pipes Water Model Rebuild and Calibration D Conduct Water System Performance Analysis for Existing and Future Conditions E Water System CIP and Master Plan Report Southlake Water Master Plan Update Project Schedule DEC JAN 2023 2024 Draft Water CIP - October 2023 Draft Water Master Plan Report - December 2023 Final Master Plan Report - January 2024 NOVAUG SEP OCTFEB MAR APR MAY JUN JUL Project Task Key Project Milestones (Dates Approximate)