February 24, 2025

Over this past winter, the team at MRMS has been out in force, solving issues that the cold weather brings. When winter comes to an end, we won’t be resting as a different set of problems will arise. As the seasons change, so too do the challenges faced by sewer and drainage systems. Each season presents unique stressors, from heavy rains in spring to freezing temperatures in winter, which can lead to significant issues if not managed effectively.

From cleanup and repair to potential environmental damage, the cost of compromised drainage systems can be huge. However, it’s not inevitable. A Planned Preventative Maintenance (PPM) schedule can mitigate the risk of seasonal problems by ensuring systems are inspected, cleaned, and repaired regularly. Robust PPM schedules will plan for the different challenges each season brings

Winter

Winter poses a serious risk to drainage systems due to freezing temperatures. Water trapped in pipes can freeze and expand, causing burst pipes or blockages. The freeze-thaw cycle also weakens pipes, creating cracks that can lead to significant structural damage.

Key Problems in Winter

Frozen and Burst Pipework

Sub-zero temperatures can cause water and sewage within pipes to freeze. As the water expands, it exerts pressure on the pipe walls, potentially leading to:

Pipe Cracks or Bursts: Frozen water can rupture pipes, resulting in costly repairs and service interruptions.
Restricted Flow: Even partial freezing can reduce flow capacity, causing backups or system inefficiency.

Snowmelt Flooding

Accumulated snow eventually melts, often rapidly during warmer winter days or sudden thaws. This sudden influx of water can overwhelm drainage systems, resulting in:

Localised Flooding: Blocked drains struggle to manage melting snow, creating puddles and icy hazards.
Erosion: High volumes of snowmelt can erode soil around drainage structures and sewer lines, destabilising them.

Clogged Drains from Ice, Debris and Fats, Oils and Grease (FOG)

Snow and ice formation, storms and human behaviours all contribute to issues for the drainage network, including:

Debris: Winter storms bring additional debris like salt, sand, and gravel, which can accumulate in drains and pipes.
Packed Snow: Plowed snow may inadvertently block storm grates, preventing water from entering drainage systems.
Blockages: Hardened grease reduces pipe diameter and increases the risk of clogs. Obstructed pipes can lead to wastewater backups, affecting homes and businesses.

Freeze-Thaw Cycle Damage

Frequent temperature fluctuations during winter create a freeze-thaw cycle, where water entering cracks in pipes, manholes, or other infrastructure freezes and expands. Over time, this cycle can:

Widen Cracks: Minor imperfections grow into significant structural failures.
Weaken Infrastructure: Persistent stress on ageing pipes and drains increases the likelihood of breaks.

Left to Right: The CCTV team surveying a pipe section with a remote reel; MRMS teams setting out on a cold winter morning; our Recycler cleaning a CSO.

Preventative Maintenance for Winter

Winterise Pipes and Systems: Insulate network assets in vulnerable areas to prevent freezing
System Inspection and Repair: Inspect for cracks or other vulnerabilities that could worsen during freeze-thaw cycles.

Pipe Inspection and Clearance: Inspect for and remove debris, sediment, and FOG build-up from pipes and drains before winter.

Spring

Spring, with its warming temperatures and increased rainfall, brings a host of challenges for drainage and sewer systems. As the season transitions, several factors contribute to the strain on these critical infrastructure components.

Key Problems In Spring

Heavy Rainfall and Stormwater Management

Spring is notorious for unpredictable and intense rainfall, leading to significant stormwater accumulation. Many drainage systems struggle to handle the sudden surge, which can result in:

Overflows: Excess water overwhelms storm drains, leading to localised flooding.
Erosion: High water flow can erode soils, damaging embankments and nearby structures.
Contamination: Overflowing sewers can release untreated sewage into the environment, endangering public health.

In regions with harsh winters, spring snowmelt adds an additional burden to drainage systems. Rapid melting caused by rising temperatures can inundate systems already taxed by spring rains. This can lead to flooding, standing water, and saturated soils, potentially destabilising underground sewer pipes.

Debris Accumulation and Root Intrusion

Spring brings blossoming trees, growing vegetation, and winds, which can increase debris like leaves, twigs, and dirt. This debris often clogs storm drains, grates, and sewer entry points, reducing flow efficiency and increasing the risk of backups and flooding.

As plants awaken during spring, tree roots actively seek water sources. Sewer pipes, particularly older or damaged ones, are a common target for roots due to the moisture and nutrients they contain. Root intrusion can cause blockages, cracks, and long-term damage to sewer lines.

Soil Movement

Freeze-thaw cycles from winter to spring can cause soil to shift, potentially affecting underground infrastructure. This movement can lead to misaligned pipes, cracks, or even pipe collapses, resulting in costly repairs.

An MRMS Operative uses a Recycler to clear a blocked storm gully and drain the road of overflowing water.

Preventative Maintenance for Spring

Regular Inspections: Check drains, pipes, and manholes for debris, damage, or signs of blockage.
Maintenance of Vegetation: Trim nearby trees and shrubs to minimise debris and reduce the risk of root intrusion.
Cleaning and Repair: Clear clogs and repair any cracks or misalignments in the system.
Upgraded Infrastructure: Consider investing in modern drainage solutions, such as high-capacity storm drains or root-resistant sewer pipes, to handle future demands.

Summer

Summer brings warm temperatures, longer days, and unique challenges for drainage and sewer systems. As the season unfolds, environmental changes, weather patterns, and human activity place added strain on these critical infrastructures.

While summer might seem harmless, heat can cause the ground to dry and shift, leading to pipe misalignment or cracks. During dry periods, tree roots seek moisture and can invade pipe systems, leading to slow drains or severe blockages.

Key Problems In Summer

Heavy Storms and Flash Flooding

While summer may be known for its warmth, it often brings sudden and intense storms. These fast-moving weather systems can overwhelm drainage and sewer systems, leading to:

Flash Floods: Short bursts of rain can produce a high volume of water in a short time, outpacing the capacity of drainage systems.
System Overloads: Sewer systems may experience backups when stormwater exceeds the designed capacity, resulting in localised flooding and property damage.

Increased Debris from Vegetation

During summer, clogged grates and pipes can lead to reduced flow efficiency and blockages, increasing the risk of system failures. Growing vegetation and storm activity contribute to additional debris entering drainage systems, such as:

Grass clippings from lawn care.
Leaves and branches from summer storms.
Litter from outdoor recreational activities and increased foot traffic.

Drought and Water Shortages

Paradoxically, summer’s heat can create drought conditions in some areas, causing soil to dry and contract. This poses specific risks to sewer systems:

Shifting Soils: Dry soil can lead to ground movement, which may crack or misalign underground pipes.
Lower Water Flow: In reduced water conditions, sewer systems may experience stagnant water, contributing to blockages, odours, and biofilm growth.

Increased Usage from Recreational Activities

Summer is a time for events, festivals, and increased outdoor gatherings, which often lead to higher water usage and added strain on sewer systems. Public facilities and storm drains near recreation areas are particularly prone to overuse, potentially causing backups or increased maintenance needs.

The MRMS Bluelight Lining team repairing damaged pipes without needing to excavate.

Preventative Maintenance for Summer

Regular Cleaning and Inspections: Clear out storm drains and sewer lines to remove accumulated debris and prevent blockages.
Tree and Vegetation Management: Trim nearby plants and responsibly dispose of grass clippings to minimise debris.
Inspect and Address Cracks or Damage: Repair cracked pipes or misaligned infrastructure to prevent further issues.

Autumn

Autumn is a challenging season for commercial and industrial drainage systems. Falling leaves and debris can clog gutters and storm drains, leading to flooding during seasonal rainstorms. As organic material decomposes, it hardens into tough blockages that require professional removal.

Key Problems in Autumn

Debris Accumulation and Root Infiltration

Autumn is synonymous with shedding leaves. While they look great, these leaves create significant problems for drainage systems.

Clogged Storm Drains: Leaves, twigs, and other organic debris accumulate in storm drains, blocking water flow and leading to localised flooding.
Sewer Blockages: When debris enters the sewer system, it can combine with fats, oils, and grease (FOG) to form blockages, reducing efficiency and increasing the risk of backups.
Sewer Line Intrusion: Roots can penetrate cracks in pipes, causing blockages or structural damage.

Increased Rainfall & Storm Surges

Autumn typically brings more frequent and consistent rainfall. This can strain drainage and sewer systems in several ways. Additionally, in coastal areas, autumn often sees the peak of storm events.

Overloaded Systems: Heavy rains can inundate systems, especially in urban areas with significant impervious surfaces like roads and parking lots.
Standing Water: Poorly maintained or undersized drains may struggle to channel rainwater, leading to pooling and localised flooding.
Flooded Storm Drains: Sudden storm surges overwhelm drainage systems, leading to street and property flooding.

Left to right: Cleaning a Storm Drain with the RoboDozer; cleaning a wet well before it is commissioned; clearing debris from a storm lake, a SuDS component.

Preventative Maintenance for Autumn

Leaf and Debris Management: Regularly clear storm drains and gutters to prevent blockages.
System Inspections: Check for cracks or misalignments in sewer pipes to address vulnerabilities before winter. Inspect sewer lines for tree roots and remove them.

Flood Prevention: Upgrade drainage infrastructure to handle increased autumn rainfall.
Runoff Management: Employ green Sustainable Drainage Schemes (SuDS) infrastructure solutions like rain gardens and permeable pavements to capture and filter runoff naturally.

The Role of Reactive Maintenance Services

PPM minimises seasonal drainage problems by keeping your systems in optimal condition year-round. Regular inspections, cleaning, and repairs reduce the risk of blockages, flooding, and costly downtime. However, even with the best preventative measures emergencies can happen. Alongside our PPM solutions, MRMS provides round-the-clock, rapid-response reactive drainage maintenance to minimise disruptions and prevent further damage. Our reactive maintenance services include:

Emergency drain clearing
Desilting to improve water flow
High-pressure water jetting
Root cutting and removal
Pipe repair and replacement

Seasonal changes can put immense stress on industrial and commercial drainage systems. By combining planned preventative maintenance with reliable reactive services, MRMS ensures your drains stay functional and efficient throughout the year.

PPM: How The Changing Seasons Impact Drainage Systems