What Causes a Blocked Manhole?

Manholes are a common sight in urban landscapes, especially in bustling cities like London. These seemingly mundane features of our streets play a crucial role in the city’s infrastructure.

The history of manholes is as intriguing as their function. Dating back to the early 19th century, manholes have undergone significant evolution over the years. Initially, they were rudimentary access points to the burgeoning sewer systems of growing cities.

As urban areas expanded and the complexity of underground utilities increased, the design and functionality of manholes evolved. They became more standardized, safer, and easier to maintain.

This evolution reflects not just a change in engineering and design but also a growing understanding of public health and urban planning.

The development of manholes is a testament to the advancements in these fields, showcasing how even the most overlooked aspects of our daily environment are the result of centuries of innovation and adaptation.

As we walk the streets of London or any other city, it’s worth remembering the hidden world beneath our feet, accessible through these unassuming portals – the manholes.

    We will store the information you provide in this form in accordance with our privacy policy Here

    Understanding Common Causes of Manhole Blockages

    Manholes play a crucial role in our urban drainage systems, yet they often go unnoticed until a problem arises. Understanding what causes blockages in these manholes can help us prevent and address these issues more effectively.

    There are two main types of manholes: public and private. Public manholes, which you commonly see on streets and sidewalks, manage the flow of wastewater and rainwater from public areas.

    Private manholes, on the other hand, are located on private properties and handle waste from individual buildings or complexes. Both types are susceptible to blockages, leading to similar drainage problems.

    Seasonal changes significantly impact the likelihood of manhole blockages. During autumn, fallen leaves can accumulate and clog manholes, a situation exacerbated by rainfall that washes these leaves into the sewer system.

    Additionally, heavy rain can carry various kinds of debris, including leaves and trash, into manholes, contributing further to blockages.

    The process of blockage in manholes is typically gradual. It starts with a slow accumulation of debris such as leaves, twigs, and litter.

    Over time, this build-up obstructs the flow of water, leading to potential blockages. If these blockages are not promptly addressed, they can cause water to back up, potentially resulting in flooding of streets or properties.

    Being aware of these common causes of manhole blockages is essential. Regular inspection and maintenance, particularly during seasons prone to blockages, can prevent many of these issues from escalating.

    Staying vigilant and proactive is key to ensuring our urban drainage systems function effectively, avoiding the inconvenience and damage caused by blocked manholes.

    what causes a blocked manhole


    Dealing with Manhole Blockages

    When you suspect a manhole blockage, it’s important to act quickly but safely.

    Here’s a step-by-step guide on how to handle these situations:

    Locating the Manhole

    The first step is to find the manhole. If it’s on your property, it’s usually located in the garden or driveway. For public manholes, they’re often found on streets or pavements.

    Ensure the area around the manhole is clear. This not only makes it easier to work but also safer.

    Safety Precautions

    Before attempting to inspect or clear a manhole, prioritize safety. Wear protective gloves and sturdy footwear to protect against sharp objects and bacteria.

    If the manhole is in a traffic area, use cones or signs to alert passersby. Never attempt to access a manhole in a busy street without proper safety measures.

    DIY Approach to Clearing Visible Debris:

    If the blockage is visible and within reach, you can try to clear it yourself. Use a tool like a rod or a long stick to gently remove the debris.

    Be careful not to push the blockage further down. The goal is to loosen the debris and allow it to flow down the sewer line.

    After clearing, flush the manhole with water to ensure the blockage is completely removed.

    When to Call Professionals:

    If the blockage is not visible or too deep, it’s time to call in the experts. Professional drain cleaners have the right tools and expertise to handle complex blockages.

    Persistent bad odors, water not draining properly, or multiple blocked drains are signs that the problem might be more serious than a simple blockage.

    Professionals can also conduct a CCTV drain survey to diagnose the issue accurately and prevent future blockages.


    Dealing with manhole blockages can be a challenging aspect of property maintenance, but with the right approach, it’s a manageable task.

    Whether you’re tackling a blockage through a DIY method or deciding to call in professionals, understanding the causes and solutions for blocked manholes is key.

    Regular checks and maintenance, especially during seasons prone to blockages, can prevent many issues.

    Remember, safety should always be your top priority when dealing with these issues.

    Frequently Asked Questions

    How often should manholes be inspected for blockages?

    Regular inspections are crucial, especially after heavy rainfalls or during autumn when leaves are likely to fall. Ideally, a bi-annual check can help identify and prevent potential blockages.

    Can household items cause manhole blockages?

    Yes, flushing inappropriate items down the toilet or sink, like wipes, sanitary products, or cooking grease, can contribute to blockages. It’s important to be mindful of what goes down your drains.

    Are there any signs that indicate a manhole is blocked before it becomes visible?

    Yes, slow draining sinks and toilets, gurgling sounds from drains, and unpleasant odors are early signs of potential blockages in the sewer system.

    About Jonny’s Drains

    At Jonny’s Drains, we understand the inconvenience and potential damage caused by blocked manholes. That’s why we offer expert services to tackle any manhole blockage issue you might face.

    Our team of experienced professionals is equipped with the latest tools and technology to efficiently diagnose and resolve blockages.

    Whether it’s a simple clearing job or a more complex issue requiring a CCTV drain survey, we’ve got you covered.

    We pride ourselves on our commitment to customer satisfaction and our ability to handle any drainage challenge.

    If you’re facing a manhole blockage or just want to ensure your drainage system is in top condition, don’t hesitate to contact us.

    Let Jonny’s Drains take care of your drainage needs, ensuring a smooth and efficient solution to keep your property safe and dry.

    Request A Call Back Today

    Let us call you when it's convenient for you. Request a callback and we will contact you as soon as possible to see what we can do for you.

    Need a drain unblocking? No problem!

    Many of my customers in Westerham, Kent report of blocked drains, be it toilet and sink blockages, blocked waste pipes or manholes. If you discover a blockage, don’t delay. I offer a 24 hour, 7 days a week service and can often unblock your drain within an hour. So if you have emergency drainage issues, contact Jonnys Drains straight away on 01959 928 853.

    Highly Experienced

    Free Callout

    Local Service


    24/7 SERVICE