How to Tell Whether a Culvert May Be Failing

Know the Warning Signs

How to Tell Whether a Culvert May Be Failing

A failing culvert may first appear as standing water, erosion, a dip in the road, or a small depression near the pipe. Those warning signs should not be ignored. A damaged or overwhelmed culvert can affect drainage, roads, driveways, nearby property, and emergency access.

Do not enter a culvert or inspect it from the roadway. Never climb into a pipe, stand in moving water, walk onto an eroded shoulder, remove a manhole cover, crawl beneath a road, or approach a culvert during flooding. Report the condition from a safe location.
🌊 Water behavior

Look for backing up

Water rising much higher on one side of the crossing may indicate a blockage, restriction, damage, or inadequate capacity.

🕳️ Ground movement

Watch for depressions

A dip, crack, soft spot, or small hole above or beside a culvert may indicate soil is being lost around the pipe.

🛣️ Road condition

Look for sinking or cracking

Pavement cracks, shoulder washout, settlement, or an uneven crossing can signal damage beneath the road.

📸 Documentation

Record changes safely

Photographs from the same safe location before, during, and after rain can show whether the condition is worsening.

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Common warning signs of a culvert problem

One warning sign does not prove that a culvert is failing. Several signs appearing together, recurring flooding, or a condition that is steadily worsening should be reported and professionally inspected.

Water backs up much higher on one side
Important warning sign

A noticeable difference in water level between the upstream and downstream sides may indicate that water cannot pass through the culvert fast enough.

Possible causes include:

  • Debris blocking the entrance
  • Sediment filling part of the pipe
  • A crushed or collapsed section
  • A pipe that is too small
  • A downstream obstruction
  • An outlet that is submerged
  • An improperly installed elevation or slope

Photograph both sides from a safe distance without standing in the road or approaching moving water.

Water flows over the road or driveway crossing
Potentially urgent

Overtopping means water is no longer passing only through the intended pipe or opening. The culvert may be blocked, damaged, undersized, or overwhelmed by downstream conditions.

Water flowing over a road can erode the shoulder, undermine pavement, hide a washout, and weaken the material surrounding the pipe.

Do not drive, walk, or stand in the flooded area. Report the roadway condition immediately to the responsible road agency or emergency authorities when public safety is threatened.

A dip, depression, or hole forms above the pipe
Potentially urgent

A depression above or beside a culvert may indicate that soil is washing into an opening, separated joint, crack, or collapsed section.

Watch for:

  • A new dip in the road or driveway
  • A soft area that continues getting larger
  • A circular hole or depression near the pipe
  • Cracks surrounding a sunken section
  • Soil disappearing near the inlet or outlet
  • Loose pavement or unsupported concrete

Keep people, animals, and vehicles away. Do not probe the hole or stand near its edge.

The road, shoulder, or driveway is cracking or sinking
Serious warning sign

Cracking or settlement near a culvert crossing may result from erosion, soil loss, pipe deformation, failed joints, poor compaction, or repeated overtopping.

Signs may include:

  • Long cracks following the culvert alignment
  • A low spot across the roadway
  • Broken pavement near the shoulder
  • A driveway slab separating or tilting
  • Loose soil or gravel washing away
  • A shoulder that appears hollow or unsupported
The inlet or outlet appears crushed, bent, separated, or collapsed
Visible structural damage

Visible deformation can reduce the opening available for water and may indicate damage extending farther inside the pipe.

Look only from a safe exterior location for:

  • A flattened or oval-shaped pipe opening
  • Separated pipe sections
  • Cracks in concrete
  • Rust-through or missing metal
  • Broken headwalls
  • Displaced pipe ends
  • Pieces of pipe or concrete in the channel

The visible opening may not show the condition beneath the road. Professional inspection may require cameras, measurements, excavation, or other specialized equipment.

Soil is washing away around the inlet or outlet
Erosion warning

Erosion around a culvert can remove the material supporting the road, driveway, headwall, or pipe.

Warning signs include:

  • A deepening channel beside the pipe
  • Exposed pipe that was previously covered
  • Undercutting around a headwall
  • Soil collapsing into the inlet
  • Fresh sand or sediment deposited downstream
  • Water flowing around the outside of the pipe

Water traveling around a culvert instead of through it can continue removing soil and worsen the damage.

Water flows around the culvert instead of through it
Possible bypass

Water may find a path beside, beneath, or over a culvert when the opening is blocked, the pipe is damaged, the structure is undersized, or the soil surrounding it has eroded.

This bypass flow can undermine the crossing and create hidden voids. It should be documented and reported promptly.

The culvert stays blocked shortly after repeated cleaning
Recurring problem

Repeated blockage may indicate that the culvert is collecting more sediment, vegetation, or debris than the system can safely manage.

Possible reasons include:

  • An upstream erosion source
  • Poor inlet alignment
  • An opening too small for normal debris
  • An inadequate slope
  • A damaged section trapping material
  • Improperly placed yard waste
  • A larger upstream drainage problem

Cleaning may still be necessary, but repeated blockage should prompt an evaluation of the cause.

Flooding continues even though the opening looks clear
Possible capacity problem

A clear inlet does not prove that the full culvert is open, structurally sound, properly sloped, or large enough.

Continued flooding may indicate:

  • A blockage farther inside the pipe
  • A collapsed or separated interior section
  • An undersized culvert
  • A submerged outlet
  • A full downstream canal or pond
  • An inlet or outlet installed at the wrong elevation
  • Insufficient slope through the crossing
The problem is becoming worse with each storm
Worsening condition

A growing depression, increasing erosion, deeper flooding, longer drainage time, or expanding pavement cracks may indicate progressive deterioration.

Photograph the condition from the same safe location after each event so the rate of change can be shown.

A culvert does not have to be completely collapsed to create a serious drainage or roadway problem.

What the water may be telling you

What you observe What it may indicate What should be checked
Water is much higher on the upstream side Restriction, blockage, damage, or inadequate capacity Full pipe interior, inlet, outlet, slope, downstream water level
Water overtops the road Culvert or downstream system cannot pass the flow Pipe size, blockage, road elevation, downstream restriction
Water flows around the outside of the pipe Erosion, pipe separation, poor sealing, or bypass flow Soil loss, voids, joints, headwalls, road support
Water swirls strongly near the inlet Partial obstruction or restricted opening Debris, sediment, deformation, interior blockage
Little or no water exits the outlet Interior blockage, collapse, poor slope, or buried outlet Pipe interior, outlet elevation, sediment, downstream condition
The outlet remains submerged High downstream water or incorrect outlet elevation Canal, pond, tide, groundwater, regional drainage level
Water takes much longer to drain than before Growing obstruction, damage, reduced capacity, or downstream backup Maintenance history, pipe condition, rainfall comparison

Signs in the road, driveway, or surrounding ground

Possible surface warning signs

  • A new dip across the road or driveway
  • Cracks directly above the culvert
  • A sinking shoulder
  • A depression beside the pavement
  • Loose or collapsing soil
  • Fresh washout after rainfall
  • Broken or tilted headwalls
  • A guardrail or sign beginning to lean

Possible hidden conditions

  • Soil washing into a pipe joint
  • A void beneath the pavement
  • A collapsed interior section
  • Failed bedding beneath the pipe
  • Water leaking outside the culvert
  • Corrosion below the visible portion
  • Damage caused by heavy vehicles
  • Repeated saturation weakening the road base

These conditions cannot be confirmed safely by a resident and may require professional inspection.

Never assume a small depression is harmless. A hole at the surface may be smaller than the unsupported area beneath it. Keep vehicles and people away until the location is evaluated.

Visible signs of pipe or structure damage

Metal culverts

Possible corrosion or deformation

  • Rust holes
  • Missing bottom material
  • Flattened sections
  • Bent or torn edges
  • Sections pulling apart
  • Soil visible through the pipe wall
Concrete culverts

Possible cracking or separation

  • Large cracks
  • Broken concrete
  • Separated joints
  • Exposed reinforcing steel
  • Displaced sections
  • Damaged headwalls or wing walls
Plastic culverts

Possible crushing or displacement

  • Oval or flattened shape
  • Torn pipe walls
  • Separated joints
  • Pipe ends shifting
  • Loss of surrounding soil
  • Damage from vehicles or equipment

A culvert problem does not always mean the same thing

Problem type What it means Common evidence
Blockage Debris, vegetation, sediment, or another object reduces the opening. Visible material, upstream backup, stronger flow after cleaning
Structural damage The pipe, joint, headwall, or surrounding support has deteriorated. Cracks, corrosion, collapse, separation, soil loss, road settlement
Capacity problem The culvert may be open but too small for the water reaching it. Repeated overtopping, flooding after cleaning, clear pipe with continued backup
Installation problem The culvert may be too high, too low, poorly aligned, improperly sloped, or inadequately supported. Standing water, sediment accumulation, poor flow, erosion around pipe ends
Downstream restriction The culvert cannot discharge because the receiving system is full or restricted. Submerged outlet, backup from canal or pond, water high on both sides

Examples of what residents may observe

Example 1: Leaves cover most of the entrance

Water backs up behind the culvert during rain. A large amount of leaves, branches, and yard debris is visible at the entrance.

Possible issue: Maintenance or blockage

The full pipe and downstream route should still be inspected before assuming the visible debris is the only problem.

Example 2: The road has developed a new dip

The pavement above the culvert appears lower than the surrounding road. Cracks are visible and the shoulder is beginning to wash away.

Possible issue: Structural or soil-support failure

Keep vehicles and pedestrians away and report the condition promptly.

Example 3: The culvert is clear but the road overtops

The opening appears clear and water is flowing through it. During repeated storms, water still rises over the road.

Possible issue: Capacity or downstream restriction

Cleaning alone may not correct the problem. Measurements and engineering analysis may be needed.

Example 4: A small hole forms beside the pipe

A depression appears near the culvert after rain and becomes slightly larger after each event.

Possible issue: Soil loss or separated pipe section

Do not fill, probe, or stand near the hole. The void beneath the surface may be larger than it appears.

How to document a suspected culvert problem

  1. Stay away from traffic and moving water.
    Take photographs only from stable ground and a safe distance.
  2. Record the exact location.
    Include the address, road name, nearest intersection, side of the road, and GPS coordinates when available.
  3. Photograph both sides.
    Show the inlet, outlet, road surface, shoulders, nearby ditch, and the surrounding area.
  4. Use the same photo locations.
    Repeated photographs from the same position make changes easier to see.
  5. Record the rainfall and timing.
    Note when rain began, when water peaked, and how long the area took to drain.
  6. Document the water difference.
    From a safe location, photograph whether water is higher on one side than the other.
  7. Record visible changes.
    Note new cracks, depressions, erosion, exposed pipe, displaced material, or increasing road settlement.
  8. Save every report number.
    Keep service requests, inspection findings, names, dates, emails, and follow-up responses together.

Useful photographs

  • Wide view of the entire crossing
  • Inlet from a safe distance
  • Outlet from a safe distance
  • Water levels on both sides
  • Road or driveway surface
  • Shoulder erosion
  • Cracks or depressions
  • Nearby homes or roads affected by flooding

Useful written details

  • Date and time
  • Rainfall amount
  • Water depth
  • How long water remained
  • Direction of flow
  • Whether the road overtopped
  • Whether emergency access was affected
  • Previous flood or repair dates
Do not use a ruler, pole, shovel, camera, or body part to probe a culvert. Moving water can pull a person toward an opening. Unstable soil can collapse without warning. Measurements should only be taken from a safe, stable location.

How to report a suspected culvert failure

Begin with the agency or private entity responsible for the road, driveway, drainage easement, or property containing the culvert.

Report these conditions clearly

  • The road or driveway is sinking
  • A hole or depression is growing
  • Water is flowing over a public road
  • The shoulder is washing away
  • The culvert appears crushed or collapsed
  • Water is flowing around the pipe
  • The crossing is affecting emergency access
  • The condition worsened after the latest storm

Ask the inspecting agency

  • Who owns and maintains the culvert?
  • Was the pipe interior inspected?
  • Was structural damage found?
  • Were voids or soil loss identified?
  • Are the inlet and outlet elevations correct?
  • Is the culvert adequately sized?
  • Was the downstream system inspected?
  • Is temporary traffic control needed?
  • What repair or replacement is recommended?
  • What report or work-order number was assigned?

Sample culvert inspection request

I am requesting an inspection of the culvert located at [ADDRESS, ROAD, INTERSECTION, OR GPS COORDINATES].

The culvert is located [DESCRIBE WHICH SIDE OF THE ROAD OR PROPERTY].

The following conditions were observed: [BACKED-UP WATER, OVERTOPPING, EROSION, ROAD SETTLEMENT, CRACKING, VISIBLE PIPE DAMAGE, DEPRESSION, BLOCKAGE, OR OTHER CONDITION].

The condition was observed on [DATES AND TIMES]. Water reached approximately [DEPTH] and remained for approximately [DURATION]. Photographs and rainfall information are attached.

Please confirm:

1. Who owns and maintains the culvert.
2. Whether the inlet, outlet, and interior were inspected.
3. Whether the pipe is blocked, damaged, separated, crushed, or collapsed.
4. Whether erosion, soil loss, or voids were found around the structure.
5. Whether the culvert has adequate capacity for the drainage area.
6. Whether the downstream drainage system was inspected.
7. Whether the road or driveway is safe for continued use.
8. What temporary and permanent action is recommended.
9. The service-request or work-order number assigned.

When a culvert condition may require urgent attention

Report the condition immediately when:

  • A public road is actively washing out.
  • The pavement or shoulder is collapsing.
  • A vehicle could enter a hole or unsupported area.
  • Water is rapidly overtopping the crossing.
  • The culvert or headwall has visibly collapsed.
  • A driveway is the only access to an occupied home.
  • Emergency vehicles may be unable to enter or leave.
  • Utilities appear exposed or damaged.
  • Floodwater creates an immediate threat to people or property.

For an immediate danger to life or an active roadway emergency, contact emergency services. For non-emergency drainage and roadway problems, contact the responsible road or property-maintenance agency.

Do not place cones, barricades, boards, fill, rocks, or equipment in a public road yourself. Report the danger and allow the responsible agency or emergency personnel to establish traffic control.

Who may be responsible for the culvert?

Culvert location Likely starting point Records to request
Beneath a county-maintained road Brevard County Road and Bridge Infrastructure inventory, inspection history, work orders
Beneath a city-maintained road City public works or stormwater department Road inventory, drainage maps, inspection records
Beneath a state road Florida Department of Transportation FDOT drainage and right-of-way records
Beneath a private driveway Property owner, HOA, or road agency Driveway permit, right-of-way permit, maintenance rules
Inside a private neighborhood HOA, developer, community district, or private owner Plat, maintenance agreement, development approval
Within an active construction project Developer, contractor, approving agency, or permit authority Approved plans, inspection reports, as-built records

What residents should not do

Do not enter or approach the pipe

  • Do not crawl into a culvert.
  • Do not reach into the opening.
  • Do not stand directly above moving water.
  • Do not stand on eroded soil.
  • Do not enter floodwater to obtain photographs.

Do not alter the system without approval

  • Do not remove a public culvert.
  • Do not replace it with a different size.
  • Do not deepen or redirect the ditch.
  • Do not place fill over a depression.
  • Do not block the inlet or outlet.
  • Do not use heavy equipment near a suspected void.
Residents do not need to diagnose the exact failure. The most useful role is to identify the warning signs, document them safely, report the location accurately, request a professional inspection, and save the results.

The bottom line

A culvert may be failing when water repeatedly backs up, the crossing overtops, soil washes away, the pipe visibly deforms, the road sinks, or a depression forms near the structure.

The problem may be a blockage, structural damage, improper installation, inadequate capacity, or a restriction farther downstream. A clear opening does not prove that the entire pipe is sound or large enough.

Stay out of the water. Keep away from unstable ground. Photograph the condition from a safe location. Report the exact location. Ask for an inspection of the pipe, surrounding soil, road support, capacity, and downstream system.

Official sources and further reading

  1. Brevard County Road and Bridge Service Request
  2. Brevard County Road and Bridge Maintenance
  3. Brevard County Floodplain Administration and Drainage Maintenance
  4. Brevard County Watershed Construction Projects
  5. Florida Department of Transportation Drainage
  6. U.S. Forest Service Culvert Resilience Research
  7. FEMA Hazard Mitigation Measures for Roads, Bridges, and Culverts

This page provides general public education and is not a structural inspection. Determining the condition of a culvert may require qualified personnel, traffic control, internal camera inspection, surveys, measurements, hydraulic analysis, excavation, material testing, and review of construction and maintenance records.

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