Stormwater Treatment and Pumping
Managing and mitigating stormwater runoff
Stormwater management is the process of collecting, conveying, storing, treating, and discharging rainfall and snowmelt runoff to protect communities from flooding, safeguard water quality, and meet regulatory discharge requirements. When rainfall cannot infiltrate the ground—across roads, rooftops, parking lots, and other impervious surfaces—it flows rapidly into drainage networks, pump stations, rivers, and receiving water bodies. Without properly designed stormwater pumping, treatment infrastructure and decision support systems, this runoff contributes to urban flooding, infrastructure damage, and the discharge of contaminants that threaten ecosystems and violate environmental permit limits.
For municipal utilities, stormwater management encompasses a broad range of interconnected challenges:
- Designing pump stations capable of handling extreme peak flows that may dwarf average conditions
- Managing combined sewer overflows (CSOs) to prevent raw sewage from reaching waterways during heavy rain events
- Treating stormwater to meet EPA National Pollutant Discharge Elimination System (NPDES) permit discharge limits before it enters natural water bodies
- Maintaining detention basins and conveyance infrastructure against the relentless buildup of sedimentation, solids, and floating debris
- Monitoring stormwater infrastructure and extreme events scenarios simulation
Climate change is intensifying existing pressures on urban water infrastructure.1 Over the past five decades, the global urban population has grown from approximately 1.2 billion to more than 4.4 billion people,2 concentrating impervious surfaces and increasing stormwater runoff in cities often served by infrastructure designed for a different era. As climate change drives more frequent and intense precipitation events3 and urban expansion continues, reliable stormwater pumping and treatment systems are becoming increasingly critical for flood resilience, public safety, regulatory compliance, and environmental protection.4
Xylem’s complete stormwater solutions
Xylem draws on more than 70 years of stormwater engineering expertise to help utilities and communities manage runoff, prevent overflows, and protect infrastructure from flooding. Together with your team, we apply proven pump station design methodology alongside monitoring and control platforms that give you real-time visibility across your entire network. From emergency bypass solutions and rental fleet support to long-term infrastructure planning, Xylem is there at every stage: design, installation, operation, and asset management. We help you deliver the performance your community depends on.
- Stormwater pumps and pump stations: Dry pit submersible pumps engineered for variable peak flow conditions in municipal and industrial stormwater applications.
- Smart stormwater management: Real-time monitoring, scenarios simulation, and control systems that optimize pump operation during storm events and provide full network visibility for proactive decision-making.
- Stormwater treatment systems: Specialty adsorptive media, UV disinfection, and filtration technologies designed to meet NPDES discharge limits across a range of contaminant profiles.
- Detention basin and sump cleaning equipment: Submersible mixers and air-water ejectors that maintain basin capacity and prevent sedimentation-driven operational failures.
- Service and support: Commissioning, maintenance programs, emergency response, and parts availability backed by a global service network.
How Xylem Helps
Enhancing community resilience with better stormwater management
Overflow prevention and regulatory compliance
Well-designed stormwater pump stations, detention systems, and real-time network control reduce the frequency and volume of combined sewer overflow events, helping utilities meet EPA Clean Water Act requirements and avoid the financial and reputational consequences of consent decree enforcement.
Flood protection for communities and infrastructure
Properly sized flood control pump stations, pump gate systems, and detention basins protect residential areas, transportation networks, and critical infrastructure from the costs of flooding—and from the damage to community trust that follows a preventable flood event.
Extended asset life and lower total cost of ownership
CFD-validated sump geometry, optimized pump selection, and proactive sedimentation management minimize clogging events, reduce emergency maintenance demands, and lower the long-term labor and parts costs that erode operational budgets year after year.
Real-time network intelligence for proactive operations
Monitoring and control platform that span individual pump performance, full station status, and watershed-wide flow modeling give operations teams the data they need to predict overflow risk, optimize pump sequencing, and act before conditions become critical.
Adaptability to climate and urban growth pressures
Upgradable pump station designs and scalable detention solutions allow utilities to expand capacity as rainfall intensity increases and urban development continues—protecting long-term capital investment and extending the useful life of existing infrastructure.
Case Studies
Flygt Axial Flow Propeller Pumps Address Chronic Flooding in El Paso, TX
Flygt axial flow propeller pumps helped protect El Paso's Chihuahuita neighborhood from recurring floods, providing energy-efficient stormwater transport, dependable operation, and a space-saving pump station solution.
Wet well wonder in a deep sewer tunnel
A deep-tunnel pumping system for Columbus, Ohio’s OARS project uses adjustable-speed Flygt pumps to manage extreme head variations and efficiently dewater a 215-foot-deep, high-capacity sewer tunnel after major flow events.
Evoqua Solution Resolves Stormwater Discharge Permit Violations
A Southern California refinery resolved stormwater discharge permit violations in five days using Xylem’s vessel-based treatment system with organoclay, carbon, and ion exchange to remove hydrocarbons and metals to ppb levels.
Manchester City: Efficient rainwater capture and reuse through data and analytics
Manchester City FC is using smart technology and rainwater reuse to reduce potable water use across its Etihad Campus. With help from Xylem’s data-driven platform, the club aims to optimize irrigation and achieve full stormwater reuse by 2026.
Frequently asked questions
Flooding can occur when rainfall exceeds system capacity, infrastructure becomes blocked, or pumping systems are overwhelmed. Utilities can improve reliability through proper pump selection, preventive maintenance, system monitoring, scenarios simulation, and regular testing to help reduce flood risk and improve resilience.
Xylem provides integrated stormwater solutions including pumps, controls, monitoring systems, treatment technologies, engineering expertise, rental solutions, and service support. These solutions help utilities, municipalities, and industrial operators manage flooding risks, improve water quality, and optimize infrastructure performance.
A combined sewer system routes both stormwater runoff and wastewater through a single pipe network to a treatment plant. A separate sewer system keeps the two flows isolated — stormwater goes to a designated outfall, wastewater goes to treatment. Combined systems create combined sewer overflow (CSO) risk during heavy rainfall: when inflow exceeds treatment capacity, untreated mixed wastewater can discharge directly into receiving waterways, creating environmental and public health impacts that are regulated under the EPA Clean Water Act.
A combined sewer overflow (CSO) occurs when a combined sewer system receives more stormwater inflow than it can convey to the treatment plant — typically during heavy rainfall — and discharges untreated mixed flows into nearby waterways. Utilities can reduce CSO frequency through a combination of detention storage (which buffers peak flow), real-time network monitoring and predictive control (which optimizes capacity before overflow thresholds are reached), and infrastructure rehabilitation to reduce inflow and infiltration (I&I) that inflates baseline flows during wet weather.
Real-time monitoring gives operations teams the data to act before an overflow event occurs rather than responding after it happens. Stormwater monitoring platforms span three levels: pump-level monitoring (tracking individual pump performance and sump water levels), station-level monitoring (full pump station status and alarm conditions), and network-level control (integrating flow data, rainfall forecasting, and hydraulic modeling across the watershed). Together, these layers enable predictive control decisions that reduce overflow frequency, optimize pump sequencing, and support a proactive operations posture.
Smart stormwater systems combine real-time sensors, IoT connectivity, hydraulic modeling, and advanced control algorithms to operate pump networks proactively — not just reactively. By creating continuously updated digital representations of the urban watershed, utilities can anticipate surge conditions, pre-position pump capacity, minimize overflow duration, and document system performance for regulatory reporting. This approach reduces flood event frequency and severity, lowers the risk of permit violations, and supports long-term capital planning with evidence-based performance data.
1. Intergovernmental Panel on Climate Change, “Chapter 11,” in Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change, accessed August 19, 2026, https://www.ipcc.ch/report/ar6/wg1/chapter/chapter-11/.
2. United Nations, World Urbanization Prospects 2025, accessed August 19, 2026, https://population.un.org/wup/.
3. U.S. Environmental Protection Agency, “Extreme Precipitation,” accessed August 19, 2026, https://www.epa.gov/climatechange-science/extreme-precipitation.
4. World Meteorological Organization, “Floods,” accessed August 19, 2026, https://wmo.int/themes/floods/.