The objectives of the MacArthur Lake Stormwater Capture Project (Project) are to contribute to regulatory compliance for the Ballona Creek Watershed by treating both dry and wet weather flows from 200 acres of urban watershed in a disadvantaged community in downtown Los Angeles. In addition to water quality benefits, the Project will offset potable water use with treated stormwater, provide water supply benefits through water recycling, and increase the recreational value of the park with a terraced water feature and educational signage. The Project will also aesthetically enhance the Park with a new pedestrian bridge designed in alignment with the park's existing Art Deco style features. The Project was first identified as one of the top 10 One Water integration opportunities in the One Water LA 2040 Plan because it requires multi-agency collaboration and closes the urban water cycle with a variety of water quality, water supply and community benefits. Extensive community engagement efforts conducted during the One Water LA 2040 Plan contributed to broad support for Measure W, a parcel tax to fund the design, construction, and operation/maintenance of stormwater projects in LA County. Since its passing in 2018, Measure W now generates $300 M/year to fund LA County's Safe Clean Water Program (SCWP) projects. This Project received funding in the first round of applications through a competitive process, and is planned for construction in 2026: it is anticipated to become the second of more than 150 SCWP projects to be implemented. Combined with the historic nature of MacArthur Park, the Project has high visibility and is primed to function as a role-model stormwater project. The Project Final Design is currently undergoing final reviews by the City of Los Angeles and is expected to go out to Bid in mid-2025, with Construction anticipated to start in early 2026. This presentation will include an overview of One Water LA and the SCWP, a summary of the Project's design components, and valuable lessons learned during the planning, preliminary design, final design, and CEQA process, such as: - Right-sizing of the stormwater infrastructure to maximize water quality benefits for both dry and wet weather conditions. - Early involvement and close collaboration between LA Sanitation (LASAN), Recreation and Parks (RAP), Bureau of Engineering (BOE), and Los Angeles Department of Water & Power (LADWP) from the start of the feasibility study through final design. - Early and meaningful community engagement with a local non-profit to build community support, employing creative outreach strategies, such as a telenovela with professional actors to educate the community on the project benefits in English and Spanish. - Special design considerations to minimize community impacts to the unhoused community in the Park, local businesses (street vendors), the Park's recreational functionality, and (public) transportation impacts. The presentation will also highlight how the original project concept idea evolved from the One Water LA 2040 Plan to the Project's 2019 Feasibility Study, and the subsequent preliminary design and final design phases. Modifications made to deliver a design that meets the SCWP's regulatory water quality objectives while also enhancing the Park and maximizing community benefits will provide practical ideas for the audience to implement in their own multi-benefit stormwater and One Water projects.

Purpose: The main purpose of this presentation is to show how the City of Houston is making their wastewater collection and transmission system (WCTS) more resilient to future growth and more frequent flooding events due to climate change through the planning efforts during two programs. Benefits: This presentation will demonstrate the how the City of Houston is planning to make their wastewater system more resilient to future growth of the service area and to the impact of more frequent flooding events due to climate change. This planning work is being done during two programs: Hurricane Harvey disaster mitigation under FEMA's Public Assistance funding program and the City's Wastewater Consent Decree. The presentation will illustrate the City's approach to planning capacity improvements and flood mitigation measures to provide its customers with the target level of service, reliability and sustainability. Abstract: Introduction In August 2017, Hurricane Harvey made landfall and stalled over southeastern Texas for one week, dropping more than 60 inches of rainfall in some areas. This resulted in catastrophic flooding throughout the City of Houston, including many of the City's thirty-eight (38) wastewater treatment plants, resulting in hundreds of millions of dollars in damages, as well as environmental and public health impacts for weeks after the hurricane. To mitigate the damages to wastewater facilities induced by Hurricane Harvey and increase the resilience of the wastewater system against future flood events, the City of Houston, Houston Public Works (HPW) sought financial assistance offered through the Federal Emergency Management Agency's (FEMA) Public Assistance funding program. To secure this funding, HPW procured four consultant teams to provide planning, preliminary engineering and FEMA funding application assistance (Figure 1). The general concept to provide greater future resilience was to either harden or eliminate the flood prone WWTPs and convey the consolidated flows to a more resilient WWTP in the area, which would be expanded to accommodate the additional flows. Additionally, flooded lift stations were also consolidated, where possible, making the system not only more resilient against flooding, but also reducing O&M costs and greenhouse gas emissions. FEMA Program Approach To develop a consistent approach in developing the preliminary engineering reports (PERs) and FEMA funding applications, expert focus groups, referred to as Tiger teams were formed. The Tiger teams were led by industry experts in the areas of hydraulic modeling, tunneling, wastewater treatment and FEMA funding. These Tiger teams worked with the four consultant teams to develop defensible methodologies to be used for this project. A methodology was developed to project future wastewater flows 50 years into the future to meet Texas Commission on Environmental Quality (TCEQ) requirements. In addition, since the flow consolidation and conveyance alternatives included tunnels, a methodology was developed to project the 100-year future flows to ensure the tunnels have sufficient capacity throughout anticipated service life. The future flow projections also allow the City to plan for future treatment plant capacity expansions (Figure 2). Mitigation alternatives were developed using the framework presented in Table 1. Alternatives were formulated to either harden flooded WWTPs or consolidate flows from the flooded WWTPs and convey them to the expanded WWTP. The methodology used to optimize the management of peak wet weather flows into the expanded WWTPs is presented in Figure 3. Peak flow management strategies (i.e., storage) could be applied upstream at the flooded WWTP, or downstream, just prior to entering the expanded WWTP. The optimization identified the least-cost combination of peak flow treatment capacity and storage facilities in each of the project areas. The cost effectiveness of the proposed solutions had to meet the criteria of FEMA's benefit-cost analysis (BCA) methodology. To meet the BCA criteria, WWTP consolidation and expansion alternatives were developed and the costs estimated. The FEMA team quantified the benefits for each alternative. This was an iterative process until an acceptable benefit-cost ratio was obtained. Houston SSO Consent Decree Approach With respect to the HPW's Consent Decree planning, a heightened focus has been placed on the reduction of rainfall-derived infiltration and inflow (RDII). RDII reduction address the root cause of wet weather sanitary sewer overflows (SSOs). Improving a collection system to convey peak wet weather flows is often a viable solution. However, the collection system is constructed on flat slopes due to Houston's topography. Building gravity sewers capable of conveying flows with a wet weather peaking factor of four or more can create operational and maintenance issues, since dry weather flows may not produce self-scouring velocities. Houston's Consent Decree states that 'if the remedial action to address the capacity restraint is to upsize the Sewer Segment, the new Sewer Segment shall be designed to prevent sewer asset surcharge during a five-year, six-hour rain event, except in situations where the remedial action design to prevent the surcharge during a five-year , six-hour rain event would be detrimental to the operation of the WCTS, in which case the remedial alternatives analysis shall include alternative measures that will be taken to correct the capacity constraint.' Based on this requirement, HPW is aggressively exploring remedial measures alternatives to reduce RDII and will consider private-side measures in addition to actions on the public-side of the collection system. HPW is aiming to reduce the wet weather peaking factors in the WCTS to a target value of four or less. This will provide a system that is resilient against dry and wet weather SSOs and is less costly to operate and maintain. The planned studies include field characterization efforts and pilot projects. HPW recognizes that implementation of RDII reduction projects in service areas included in the FEMA program may require that the FEMA flood hazard mitigation projects be downsized. Status of Completion The PERs and FEMA funding applications were submitted to FEMA in February 2021. HPW entered the Consent Decree on April 1, 2021, and capacity remedial measures planning is in progress. Per the Consent Decree, all system improvements must be constructed by April 1, 2036. Conclusion: The City of Houston's wastewater system planning will yield a system that will not only provide the target level of service into the future but will also provide greater resiliency against climate-induced flooding, while being cost-effective for its customers. The long-term plan consists of hardening or eliminating flood-prone WWTPs and lift stations and conveying flows from eliminated facilities to expanded and optimized WWTPs. Addressing the root cause of wet weather SSOs through RDII reduction efforts is a priority of Houston's Consent Decree program and will help to reduce the size and cost of wastewater system improvements for the benefit of its customers and provide a system that is more efficient to operate and maintain, while also reducing dry weather SSOs.

The City of Ft. Myers contracted GHD to develop a Digital Master Plan for their drinking water, wastewater, and reuse systems. The goal of the Team was to identify projects prioritized by risk, condition, and capacity in the Capital Improvement Program (CIP). The development of the CIP differed from a typical Master Plan because it used the EPA Asset Management framework to determine the best blend of investment into maintenance, operations, and capital projects to sustain performance while minimizing lifecycle costs at an acceptable level of risk. The plan was leveraged through a cloud-based decision-making platform by integrating the available tools, processes, and information to make informed decisions, and is designed to inform data driven decision support quickly without ambiguity. Master Planning is an important component of any municipality's program to meet future needs. This 'roadmap' is designed for short-, medium- and long-term planning horizons for future growth, water supply, wastewater management and water reuse. Tasks to help the City improve investment decisions and have more information available on their assets included developing an asset hierarchy, risk framework, risk analysis, and project prioritization for linear assets. The approach to the Capital Improvement Planning task was using age and capacity as failure mode triggers in risk calculations to develop projects and determining project prioritization. Typically, master plans provide a static presentation of future conditions. However, for the City, a dynamic plan was developed by prioritizing projects using management strategies that included a combination of capacity, risk and condition. Priority Level 1 and 2 are given the highest priority (replacement as the intervention strategy) since capacity deficiencies is considered the imminent failure mode. Priority levels 3 to 5 (Rehabilitation/Monitoring as the intervention strategy) are purely based on condition of the asset and has been divided according to the core-risk scores. The intervention strategies for assets are updated dynamically through the cloud-based decision-making system considering the uncertainty and change that occurs over time to reduce inefficiencies and shortcomings of planning for a static predicted future. Project prioritization based on the core risk scores and the improvements proposed through hydraulic modeling for each planning horizon can be visualized in a digital format for ease of presentation and use. As new data are available; these models are changed so the City can have better insight of their system and the investments needed to maintain their service to their customers. This digitized plan using risk-based approach provides a positive return on investment, reduces operating costs, and lowers asset failure risk. The platform greatly enhanced knowledge of the City's linear assets with respect to knowing the remaining useful life and relative Consequence of Failure (CoF). The outcome is a future state structured for continued successes in meeting future needs and challenges. The presentation will illustrate with a demonstration of the application of the framework, explain why it is important to plan for uncertainty, and provide the benefits of digital plan. Using this approach and technology will enable municipalities create robust and flexible long-term strategies that will also employ the best use of municipal dollars.

A high density area undergoing rapid redevelopment in the City of Aurora (City) experienced historical flooding due to undersized stormwater infrastructure constructed in the 1970s. As a result, the City prioritized implementation of the Fitzsimmons-Peoria Stormwater Outfall Project to comply with current stormwater standards and provide much needed flood mitigation. The project was a large-scale effort that replaced approximately 15,000 feet of aging, 24- to 96-inch storm drain through a highly urbanized area that is undergoing rapid redevelopment. The project improved flood protection for approximately 230 residences and 40 businesses. Following preliminary design, Carollo assisted the City in contracting a Construction Manager at Risk (CMAR) contractor, BT Construction. Final design efforts were completed as a collaborative team consisting of the City, the CMAR contractor, and Carollo. Together, the team evaluated alternatives to mitigate site constraints throughout the project while minimizing public disruption and project cost. Carollo constructed a computer model using InfoWorks ICM with 1-D and 2-D components. Pipeline alignments were evaluated for hydraulic capacity and selected with consideration to construction sequencing, construction duration, protection of existing utilities, minimizing disruptions to traffic, and project cost. Carollo also performed HEC-RAS modeling of Sand Creek utilizing the existing published FEMA FIRM maps and base flood elevations with new flow rate inputs for the project basin. While the discharge flow rate increased significantly, the discharge time was well ahead of the peak attenuation of base flood elevations at the discharge location. Therefore, our team was able to prove a no-rise condition and avoid the need to submit a LOMR. Most of the pipeline was constructed using open trench construction with passive shoring (trench boxes). Four major arterial roadways required large diameter trenchless crossings. The variability of ground conditions required a combination of open face tunnel boring machines (TBM) for two of the tunnels and closed face microtunnel boring machine (MTBM) for the other two crossings. The project team evaluated each construction technique with consideration to cost, feasibility, safety, and minimizing public impact. The project also required large manholes and junction structures which were designed as a combination of both cast-in-place and pre-cast structures, with a preference for pre-cast to minimize construction duration where feasible. Now fully complete, the new storm drain system has the capacity to collect and convey the 100-year storm event to the discharge at Sand Creek. Using the CMAR delivery method, the City was able to develop alternatives during the design phase that improved basin stormwater management, mitigated risk, minimized public impacts, and totaled an overall cost within the Contractor's $31M Guaranteed Maximum Price.

The Central Everglades Planning Project (CEPP) New Water Everglades Agricultural Area Stormwater Treatment Area (EAA-STA-A-2), herein after referred to as A-2 STA, consists of approximately 7,000 acres of land and is a principal component of the EAA Storage Reservoir and Treatment Wetland Project. The purpose of the project is to further reduce the number, return frequency, and severity of undesirable, damaging high-volume discharges from Lake Okechobee, thereby improving salinity and water quality conditions in the St. Lucie and Caloosahatchee Estuaries. Hydraulics near the proposed structures of the A-2 STA Project could be challenging when considering combinations of low/high flow-stage conditions. Velocities could be excessively high, and depths could create undesirable conditions to the operation of such structures that could not be properly identified with the use of one-dimensional (1D) or two-dimensional (2D) modeling. This paper discusses modeling results associated with the design of two critical project features: (1) the S-619 Discharge Structure, a triple barrel, 10-ft x 10-ft box culvert, to be constructed under the STA 3/4 Inflow Canal to allow treated water from the A-2 STA to flow south in the Miami Canal; and (2) the S-640 Pump Station, a temporary pump station that will deliver water to the A-2 STA during an interim period while the A-2 Reservoir is being constructed. Simulation results showed that the original design could lead to undesirable hydraulic conditions, such as eddies. This prompted modifications to the original design by the Design Team to improve the hydraulics near these structures. The results of the CFD analysis provided detailed predictions of hydraulic parameters in and around the structures, offering additional insight to the Design Team and the South Florida Water Management District regarding their capacity and performance under different hydraulic and hydrologic conditions. As such, the modeling results were key input in the decision-making process involving stakeholders regarding how the various conveyance channels and structures would be operated and maintained during the project's lifespan.

The City of Austin's water and wastewater utility, Austin Water, operates 143 lift stations and manages a sprawling network of approximately 2,927 miles of wastewater pipelines. Among these is the Great Hills Lift Station, located at 9009 ½ Spicebush Drive, which has reached the end of its expected service life. This station, positioned within an environmentally sensitive area near the Bull Creek tributary, plays a critical role in wastewater management and supports the City's vision for sustainable infrastructure. Given its current state, the rehabilitation and replacement of this facility have been prioritized under Austin Water's efforts to ensure resilient wastewater services for the future. Lift stations like Great Hills are integral to Austin Water's system, serving to pump wastewater from low-lying areas to higher elevations where gravity can aid its movement. With over three decades of operation since its construction in 1985, the Great Hills Lift Station has become a focal point for infrastructure upgrades. Its modernization aligns with recommendations from the 2021 Winter Storm Uri After Action Report, underscoring the need for reliable facilities considering extreme weather events. Background and Location The Great Hills Lift Station occupies a wastewater easement at the end of a narrow, 300-foot driveway nestled between two residential properties. The site, approximately 15 feet north of the 100-year floodplain, is within Water Quality Transition Zone and adjacent to Bull Creek. Its location presents unique challenges for construction and maintenance due to steep access, environmental restrictions, and proximity to residential properties. These factors demand careful evaluation of design alternatives to minimize disruption while meeting operational and environmental standards. Existing Infrastructure The current facility includes two 10-foot diameter concrete wet wells, 220-square-foot dry pit reaching a depth of 31 feet, and two 150-horsepower pumps. Additionally, the station incorporates electrical equipment, instrumentation panels, and flowmeter vault located outside its fenced boundary. Wastewater flows into the lift station via three gravity mains and is pumped out through 16-inch ductile iron force main. However, the aging infrastructure and operational constraints necessitated a comprehensive upgrade to meet modern standards. Feasibility Study and Design Alternatives Austin Water engaged K Friese + Associates (KFA) to evaluate improvement options for the lift station. Four primary alternatives were explored: 1. Reusing the existing wet well & This would involve structural evaluations, cleaning, and modifications. However, the site's environmental and access limitations rendered this option impractical and cost-prohibitive. 2. Constructing a bypass tunnel & A 4,500-foot tunnel bypassing the lift station was considered but was dismissed due to high costs and anticipated construction challenges. 3. Building a new wet well east of the existing site & This option involves rehabilitating the northern wet well to collect inflows and constructing a new wet well within the current wastewater easement. 4. Building a new wet well west of the existing site & While feasible, this would require additional easement acquisition, adding complexity and cost. After evaluation and discussions with the City, the east site layout was selected as the most viable solution. This plan ensures minimal disruption to the surrounding area while addressing operational and environmental requirements. Proposed Project Features The new design includes the installation of a 12-foot diameter polymer concrete wet well, replacing the originally proposed 16-foot diameter wet well to accommodate site access constraints. Additional components include concrete valve vault with stainless steel access hatches, 10-foot jib crane, and modernized electrical panels. A 12-foot retaining wall will improve site accessibility and stabilize the area. The project also integrates odor control measures, force main upgrades, and a water quality pond to offset increased impervious cover. Pump Selection and Electrical Enhancements System curves were developed to select pumps capable of handling a flow rate of 2,000 gallons per minute (GPM), slightly exceeding the station's current capacity of 1,890 GPM. To comply with City of Austin and Texas Commission on Environmental Quality (TCEQ) standards, the design includes one operational pump and one backup pump for redundancy. Electrical improvements feature a natural gas generator, replacing the original diesel-powered unit, to align with sustainability goals. Coordination with Texas Gas was instrumental in ensuring the availability of natural gas for the generator. Environmental Considerations The project site's sensitive ecological setting necessitated thorough environmental assessments. Species such as the Golden-Cheeked Warbler, Jollyville Plateau Salamander, and endangered karst invertebrates were identified in the area. Consequently, construction timelines were extended from 18 to 30 months to accommodate nesting periods and implement stormwater controls to protect local wildlife. Tree mitigation measures, including the preservation of heritage trees and replanting native species, were also incorporated. Permitting and Community Involvement Obtaining the required permits was multifaceted process due to the site's location within Critical Water Quality Zone (CWQZ) of Bull Creek. Variances from the City of Austin's Land Development Code were necessary to proceed with the project. Additionally, extensive neighborhood outreach was conducted to address community concerns and maintain transparency throughout the pre-construction phase. Construction Progress and Challenges Construction began in November 2024, with completion anticipated by August 2026. Key milestones include the placement of the new wet well and the casting of the valve vault, while the existing lift station remains operational. However, the project has faced challenges, including: - Staffing continuity issues: Turnover among City personnel required the design team to prioritize knowledge retention by maintaining consistent leadership. - Restricted workspace: Limited easement boundaries and steep access necessitated innovative construction sequencing and real-time coordination with operators. - Supply chain disruptions: Delays in materials prompted the team to implement adaptive procurement strategies to stay on schedule. Lessons Learned and Broader Impact The Great Hills Lift Station project illustrates the complexities of modern wastewater infrastructure upgrades in environmentally sensitive areas. By balancing community needs, environmental stewardship, and engineering innovation, this project sets precedent for future improvements within the City of Austin's wastewater system. Adaptive design strategies, phased execution, and sustainability-focused solutions highlight the importance of strategic planning and collaboration in addressing urban infrastructure challenges.

This paper presents a sedimentation risk evaluation via modeling for a sanitary sewer siphon system design project in Carrollton, Texas and Farmers Branch, Texas, suburbs of Dallas, Texas. The audience will learn about selecting dry and wet weather hydraulic conditions to use for evaluating sediment, how to use modeling to proactively identify the predicted locations and severity of sedimentation risks to assist designers and utilities to select design alternatives, predict sedimentation accumulation, and incorporate sedimentation control and maintenance strategies during the design phases. The Trinity River Authority (TRA) of Texas is the largest water and wastewater service wholesale provider in Texas. TRA is in the process of developing rehabilitation and replacement plans for portions of its Central Regional Wastewater System (CRWS) Elm Fork Interceptor. The project involves the design of three channel crossings. For the crossing at Cooks Branch (Figures 1 and 2 ) in the City of Carrollton, the proposed crossing is an inverted siphon (hereafter, 'siphon') with parallel 42-inch and 66-inch pipes (Figures 3 and 4). There is a proposed weir upstream of the 66-inch barrel, so it only conveys the wet weather flow (WWF), and the dry weather flow (DWF) will only pass through the 42-inch pipe. The siphon is sized to convey projected 2070 future peak WWF during a 5-year design storm. Since the DWF is much lower than the WWF, the designers and TRA had concerns about sedimentation issues in the siphon at low-flow velocities. TRA has a hydrologic and hydraulic model in Autodesk InfoWorks ICM. The model can perform DWF and WWF projections and hydraulic grade line simulations of the collection systems for existing and design conditions. It was proposed to use ICM's water quality module to analyze sediment fate and transport for the siphon system. The Ackers-White method is chosen for the Erosion / Deposition Model. ICM can simulate two sediment fractions independently, but only one fraction (SF1) was used for this analysis, assuming the suspended solids particle size compositions and settling characteristics have no significant variations that warrant refined differentiations. The solids size is based on the average sediment particle size parameter of d50. Based on literature references, average and high sediment parameter values for particle sizes d50, concentrations, specific gravity and settling velocity were used for the evaluation (Table 1). The high sediment parameters represent high risks of sedimentation accumulation for the worst conditions. Long-term historical rainfalls were used for WWF projection as it occurred in the area and are expected to repeat in the future. Historical annual rainfall data (1899-2023) from the Dallas/Fort Worth (DFW) International Airport weather station was collected from NOAA's National Weather Service website and statistically analyzed (Figure 5). The lowest annual rainfall is 17.91 inches in 1921. The median rainfall is 33.59 inches in 2021. Unfortunately, finer time step (15-minute) rainfall data necessary for modeling is not available for the DFW station. However, the 15-minute time step rainfall data for recent years is available at a nearby Fort Worth WSFO Station. The data from 2000-2013 (Table 2) shows the 2008 rainfall of 12.4 inches is less than the 1921 rainfall, and the 2009 rainfall of 34.5 inches is close to the median rainfall of 2021. The two calendar years of rainfall contain a very dry year-duration with higher risks of sedimentation accumulation followed by an average year with average wash-out condition. Therefore, it is considered a reasonable rainfall period to evaluate the sedimentation risks for the siphon. A 5-year design storm was added at the end of 2009 to evaluate additional cleaning effects at the design condition. The simulated flow to the siphon is shown in Figure 6. The peak flow is 78.6 mgd for the 5-year design storm. The following summarize the results (Table 3) and conclusions of the evaluation: Average sediment parameter inputs: - No sediment issue is predicted for the 42-inch barrel. - For the 66-inch barrel: --Upstream Junction: The sediment accumulation at the weir location is due to stagnant water. --The influent pipe to the Downstream Junction: It has incremental sediment build up during dry weather periods due to low recirculation flow from the 42-inch pipe. The downstream end can be washed out by most of the storms. The upstream end has accumulations. High sediment parameter inputs: - The 42-inch barrel: --It can have 3.5 hours of sediment accumulation during early morning low-flow period, but the sediment will be washed out during higher flow hours (Figure 7). - The 66-inch barrel: --Upstream Junction: Sediment accumulation occurs for the first two sections downstream of the weir due to stagnant water (Figures 8 and 9). --The influent pipe to the Downstream Junction (Figure 10):It has incremental sediment build up during dry weather periods due to low recirculation flow from the 42-inch pipe. The downstream end can be washed out by most of the storms. The upstream end has accumulations. --The rest of the pipes can self-clean (Figure 11) - The sediment doesn't increase the head loss significantly for the 5-year storm after a 2008-2009 rainfall condition. However, it could be further verified by detailed modeling such as computational fluid dynamics (CFD) modeling. Based on the evaluation, the following were recommended: - The current Cooks Branch Siphon sizing is confirmed and recommended. - A Texas Commission on Environmental Quality (TCEQ) variance may be required as the weekday peak DWF velocity is less than 3.0 ft/s. - Consider the following sediment management options for the 66-inch pipe: --A back flow prevention device. --An inspection program and maintenance plan to remove the accumulation periodically. --Supplemental water for sediment cleansing. --Sluice gate at 42-inch pipe inlet. Conclusion/Recommendation: The sediment accumulation in collection systems can be modeled in conjunction with Hydrologic and Hydraulic models with available modeling software. The model uses typical sediment and erosion/deposition theories and equations. Reasonable sediment parameter ranges and DWF/WWF projections are required for the modeling. Using average and more conservative conditions for both sediment parameters and rainfalls can provide sensitivity analysis of sediment risks in the systems. The model can identify potential sediment accumulation locations/causes and help refine the designs to minimize the impact by incorporating operation and maintenance strategies into the design. Status of Completion: At the time of submittal, the study confirms the design and sizing of the Cooks Branch Siphon. Based on the sediment location/cause results, the design team is considering several options to manage the potential sediments. Similar analysis will be applied to two additional channel crossing sites.

After a deficiency was experienced in one of their lift stations, the North Texas Municipal Water District requested for their wastewater system meters to be evaluated for accuracy and functionality for 141 of their billing meters, of which 90 were for billing purposes. The goal of the evaluation was to evaluate the accuracy and functionality of the existing meters. Using data recorded at five-minute increments from January 2022 to March 2024, meter downtime analysis, flow balances, and comparisons with billing data were conducted. Wastewater systems use meters to record flow rates of wastewater flowing throughout to determine how much to bill customers. If meters are calibrated accurately and placed in strategic locations, a clear picture on how the system cascades can be painted. If not, unmetered flows from undeterminable sources occur leading to potentially inaccurate billing of customers. A combination of statistical methods was employed to assess the accuracy of each meter. First, flow data was compiled using Python scripts to organize data for easier processing in the future and graph raw data and calculate daily averages. Daily averages were calculated using a rolling 24-hour sum to eliminate noisy data. Next, the meter data and monthly billing data were graphically compared and triaged into layers of severity based on discrepancies noticed. The severities ranged from a few months of no readings or spikes to obvious magnitude differences, with highest severity noticed in meters that were not metering over the two years of data. By triaging the meters, the municipality would know which meters to target first for maintenance and which to ignore in an efficient manner. Then, a meter downtime analysis was conducted to determine which meter would need to be properly calibrated or replaced. The percentage of how often the meter was down, which was determined by a threshold decided upon after manually inspecting the data, was calculated and used to highlight meters that needed maintenance or replacement. Finally, a flow balance of the system was conducted. Three general cases were identified. The ideal case was when the basin is under metered by around a 10% to 20% margin due to inflow and infiltration in the gravity mains. The other two cases were over metering and under metering. Over metering was noticeably caused by possible double counting by meters near a treatment plant or inaccurate metering and warranted a recalibration if the problems occurred more recently or replacement if it had been a constant issue. Under metering was noticeably caused by unmetered residential flows in between meters, significant down time, which was verified by the meter downtime analysis, or inaccurate metering which warranted a recalibration, replacement, or relocation of a meter. The presentation is intended to inform the methods on processing and assessing data from existing flow meters to assist a municipality in managing their assets.

Introduction: Houston's wastewater infrastructure is vast and complex, serving over 2.3 million residents through 38 wastewater treatment plants, approximately 380 lift stations, 5,800 miles of gravity sewers, and 134,000 manholes. In addition to the operational challenges inherent in maintaining such a large system, Houston must also comply with strict regulatory requirements under a federal consent decree, which mandates specific actions to prevent sewer overflows and improve aged infrastructure for system reliability. While addressing the compliance of consent decree, the city is also preparing for the period beyond the consent decree, it is adopting a forward-thinking approach to infrastructure management that emphasizes operational efficiency, regulatory compliance, and resilience. To address these demands, Houston is applying advanced technologies such as data integration, real-time monitoring, and predictive analytics through the Advanced Infrastructure Analytics Platform (AIAP), a 'Platform of Platforms' built on AWS Data Lake. AIAP integrates multiple operational and planning systems to enhance data-driven decision-making and optimize the management of the city's wastewater infrastructure. This paper explores how Generative AI, with a specific focus on Retrieval-Augmented Generation using AWS Bedrock and Amazon Q, is transforming Houston's wastewater management, providing critical insights into operational performance, predictive maintenance, and long-term infrastructure planning. LS plays a vital role in areas where gravity alone cannot transfer wastewater effectively. LS pumps act as the heart of the system, maintaining flow and preventing backups. Any disruption can ripple through the system, impacting public health and safety. By applying predictive failure methods, we can better protect these essential components and the communities they serve. Objective: The primary goal of this study is to: - Determine the status of LS operations at Risk using SCADA data - Develop pump downtime risk profiles for each LS to serve as a baseline - Track and evaluate the risk profiles against the baselines - Suggest a predictive maintenance plan This study presents a data-driven method using SCADA pump status data to monitor and evaluate the performance and risk of LS. By detecting the early signs of potential failures, it enables proactive maintenance and necessary actions. The approach provides a structure risk analysis, helping to prioritize maintenance for inefficient LS, effectively focused on the most critical issues to prevent high-risk incidents. Data preparation/methodology: We conducted EDA on historical pump performance data and developed a risk analysis approach that categorizes lift station conditions into three levels (Normal, Medium, and High Risk) based on SCADA data, considering the number of pumps in each station and their downtime, with traffic light colors representing each level. This method pinpoints high-risk stations, forecasts future risks based on current conditions, and culminates in a risk matrix to evaluate the station's condition based on pump functionality. To streamline the approach, a modern data architecture was implemented, with AWS data lake features being used to collect, store, and process large datasets. Scalability and reliability in analytical workflows were ensured by this setup, which efficiently managed extensive data volumes. Results/Key Findings: By analyzing SCADA data on pump operational hours, downtime frequency and the total number of operating pumps at each LS, the system identifies how many pumps are functioning well and how many are not. To assess LS risk based on pump performance, a new method is established, using traffic light indicators to classify LS conditions into three categories: normal operation (Green), medium risk (Yellow), and high risk (Red). Historic data revealed that stations transitioning from Green to Yellow often progress to Red without prompt intervention, highlighting the potential for early risk forecasting. Our method was validated using Sanitary Sewer Overflow (SSO) data, which commonly occurred near lift stations with higher pumps downtime risks. Discussion/Implications: The findings of this study contribute significantly to the field of wastewater infrastructure management by offering a proactive, data-driven approach to LS health assessment. The predictive risk model facilitates timely interventions, reducing the likelihood of pump failures and system overflows. This approach also enables better resource allocation by prioritizing high-risk LS for further assessment or renewal. Conclusion: In conclusion, this study introduced a novel approach to assess the health of LS and predict early warning signs of risk using SCADA pump status data, enabling intervention before the stations reach the danger zone. To achieve this goal, EDA techniques were applied alongside AWS data lake capabilities. The study enables proactive maintenance strategies by identifying underperforming LS, while systematically maintaining and upgrading assets to promote long-term sustainability.

Martin Road Lake in Amarillo, Texas, experienced flooding issues despite a capital project to enhance flood management and storage capacity. HDR's integrated solution, developed with public input, included fishing amenities and erosion repairs. Completed in 2023, the project successfully mitigated flooding during 100-year rain event and improved community recreational use. Martin Road Lake is an existing playa lake which impounds surface water runoff in the northeast portion of the City of Amarillo, Texas (City). The watershed contributing to Martin Road Lake drains approximately 1,658 acres and has several outfalls into the playa lake. This particular area is susceptible to flooding and thus the City began construction on several capital projects to improve the area. The City was nearing the end of construction in 2013 on one of these capital projects to lower the 100-year flood plain and increase the storage volume of the playa lake. This project required excavating an adjacent playa lake that would be hydraulically connected by box culverts under Martin Road. This portion of the project was completed successfully, however protection of its outfalls into the playa lakes were severely damaged by flash flooding prior to completion of the overall project. Several rainfall events after construction further eroded significant rills into the slopes of both the west and east playa lakes, and undermined the segmental concrete block flumes at several outfalls. HDR accompanied the City on a site visit in April 2017 to assess the conditions. Around the same time frame, the Parks Department had completed a master plan for Martin Road Park and Gene Howe Park that included providing access to the lake as a fishing amenity. Both lakes were highly utilized by the citizens for recreational activities along the trails and parks, but more over for fishing. The City tasked HDR with developing an integrated solution that would increase storage capacity for flooding, provide an alternative means for fishing that included ADA accessibility and accounted for the highly variable water surface of the playa lakes, while also repairing the eroded banks of the playa lake slopes and its outfalls. HDR knew that a long-term solution addressing these key issues would require buy in and even contributions from the project stakeholders. Some of the stakeholders included the City Parks Department, Texas Parks and Wildlife, and the citizens of Amarillo. HDR and the City held several public meetings to inform the citizens about the project, take note of their concerns, and incorporate design features to address those concerns. One of those public meetings included three site alternatives for the proposed fishing amenity. At these meetings the citizens voted on their preferred layout. One of the options provided a fluctuating pool elevation for the proposed fishing amenity as a part of the playa lake, another option provided a separate fishing amenity that was hydraulically connected to the playa lake, and the final option was a standalone fishing pond that was not hydraulically connected to either playa lake. Ultimately the citizens had a say in the final arrangement of the new park features, and HDR presented the final layout and its recommended erosion and outfall repairs to City Council prior to beginning detailed design. HDR began design in early 2018 and the first phase of the project bid later that year. Phases 3 and 4 were completed by the summer of 2023. The project has now completed its warranty period, and the citizens are extremely happy with the project outcome. The fishing amenity is being stocked by Texas Parks and Wildlife, aquatic vegetation/landscaping and air diffusers were added as a part of the fishing habitats to promote water quality, and the slope improvements at the playa lakes increased the storage capacity and thus reduced the flooding in the area. During the summer of 2023, the City experienced a 100-year rain event and the only playa lakes in the City that did not overflow that summer were the two located at Martin Road Lake. HDR and City of Amarillo are extremely proud of this project and are underway with applying similar improvements on other City Playa Lakes. This project is a great example of improving the Communities we work and play in while providing Integrated Solutions for Playa Lake Flooding and Fishing Pond Management. We would like to the opportunity to co-present this project and illustrate the collaborative public involvement in the final design features and how technology was used to expedite repairs undermining adjacent roadways.

The purpose of this presentation is to discuss alternatives to managing stormwater flows through natural systems that can benefit separate and combined sewer systems. The benefits of the presentation will include informing participants on the benefit of the application and will discuss key lessons learned that should be considered early in the planning phase to improve outcomes and reduce costs. The City of Lomita, located in Los Angeles County, is implementing a stormwater capture project that diverts flows from the 85th percentile rainfall event to a subsurface infiltration gallery located beneath the City Hall lawn, which equates to a design storm volume of 5.4 acre-feet. The project provides a series of benefits to the City and to residents by removing the volume of flow from the storm drain system. This project will alleviate flooding, remove urban watershed pollutants from being conveyed to the receiving waterbody, and provide groundwater recharge, an important aspect in areas prone to drought. By managing the stormwater in a fully buried system, it allows for full use of the site on the surface. While this project involves diverting flows from a municipal separate storm sewer system, the concept could provide similar benefits to combined sewer systems by diverting stormwater at a point prior to comingling with sanitary sewer flows, thereby alleviating CSOs during high flow events. Subsurface infiltration provides an effective means of managing stormwater, though there are several factors that must be considered prior to implementation. The City of Lomita's project encountered several obstacles which were resolved during the preliminary design phase, including identification of a past land use at the original site that posed a potential water quality risk to the groundwater basin as well as the results of geotechnical investigations that necessitated a shift in the type of subsurface infiltration being designed. Lomita remained flexible to modifications, and the revised design accommodated these conditions, and the lessons learned may improve the outcome of future projects. The project has been partially funded through the County of Los Angeles' Safe, Clean Water Program, a voter approved measure designed to fund stormwater and water supply projects throughout the County. This presentation will describe the project's intended outcomes, lessons learned, and key takeaways for those embarking on similar projects. It would appeal to municipalities managing stormwater and wastewater conveyance systems and those responsible for compliance measures. The project is currently in the design phase, which will be complete or near completion at the time of the conference.

Over the course of two decades, the City of Davenport, Iowa, has sought to develop an overall hydraulic strategy and hydraulic model for its major trunk sewer networks to determine anticipated peak-hourly wet-weather flows and identify conveyance capacity deficiencies. In 2016, field work verifications and a flow monitoring study were completed, which informed the development of a desktop hydraulic model for the Duck Creek sewershed. The hydraulic model indicated the Duck Creek North trunk sewer was severely hydraulically overloaded, leading to periodic sanitary sewer overflows and basement backups, while the West Diversion Tunnel (a deep tunnel interceptor sewer up to 96' diameter that bisects the Duck Creek North trunk sewer and was constructed to relieve overloading some two decades prior), was significantly underutilized and had excess capacity during the same events. During this same period, the City had been experiencing growth in industrial areas upstream of the Duck Creek North trunk sewer and sought a methodology to optimize its sanitary sewer capacity to eliminate backups and overflows, while providing additional capacity for economic development and growth. McClure completed a systemwide hydraulic strategy study and recommended low-cost modifications to the West Diversion Tunnel to relieve pressure on the Duck Creek North Sewer. Additionally, upstream sanitary sewer improvements were recommended to provide additional capacity to growth areas north and west of the City's existing collection system, which had the added benefit of connecting to a small, satellite controlled-discharge lagoon treatment facility the City has been operating. The primary project challenge was accomplishing these goals while minimizing impacts to other City amenities, including a popular recreational trail, as well as impacts to private landowners, given limited available financial resources. The Duck Creek Sewer Interceptor Extension project consists of approximately 26,600 LF of sanitary sewer, ranging in diameter from 54' to 18' at depths up to 35 feet below grade. Approximately 21,700 LF is 36' diameter or greater having an average depth of 25 feet. The project extends from the terminus of the West Diversion Tunnel, west along Duck Creek to Interstate 280, and south to the West Locust Industrial Park. Following completion, the satellite lagoon treatment facility will be subsequently abandoned and decommissioned. Along the alignment, there are seven creek crossings which were planned to be constructed using open-cut construction and temporary cofferdams. Additionally, the proposed sewer route also crosses the Iowa Interstate Railroad, two arterial streets critical for traffic flow in western Davenport, as well as Interstate 280. Due to sandy soils, persistently high groundwater, precise grade requirements, and complex regulatory permitting requirements, these crossings were designed to utilize closed-face slurry microtunneling as the allowable method, a highly specialized trenchless construction technology typically performed only by regional or nationwide specialty contractors and uncommon in Iowa. After 18 months of design and permitting, the project was bid and awarded in Fall 2023. The estimated construction cost of $16.5 million was funded by local American Rescue Plan Act (ARPA) funds and without the need for additional sewer enterprise revenue debt. The project is currently on track to be completed by the end of 2026. This presentation will focus on the technical challenges experienced during the design process, including deep open-cut construction and long trenchless crossings, as well as value engineering opportunities in construction specifically related to trenchless construction, the process by which those opportunities were evaluated, and how such alternative methods that have provided significant value to the City. Lastly, the presentation will conclude with lessons learned that can be applied to future projects in the Upper Midwest.