Commercial Storm Sewer Services in Denver and Aurora

Storm Drain Camera Inspection and Scoping

Camera inspection of storm drain lines shows the current condition of the underground pipes, identifies debris accumulation and blockages, locates structural failures in pipe sections, and confirms the flow path from catch basin to outlet. Storm drain pipe condition in Denver is frequently unknown because the system is rarely scoped unless a drainage problem becomes severe.

We recommend scoping storm drain lines on properties that have never had the system inspected, on properties where surface flooding continues after catch basin cleaning, and on properties where any structural repair is being planned. Camera footage of the storm line is the baseline documentation that tells the property what it has and what condition it is in.

Storm Drain Cleaning and Hydro Jetting

Blocked or restricted storm drain lines, not just blocked catch basins, produce surface flooding when the underground pipe cannot pass the inflow rate from the basins above. Hydro jetting clears sediment, debris, root intrusions, and organic accumulation from storm drain pipes. We run the camera before jetting to confirm pipe condition and after jetting to verify the line is clear.

Parking lot storm drain lines that have not been cleaned in years accumulate gravel, leaves, and compacted sediment that restricts flow significantly. A drain carrying years of accumulated sediment can handle significantly less runoff than it was originally sized for. Cleaning restores the intended flow capacity.

Catch Basin Repair and Structural Maintenance

Catch basin structures deteriorate over time. Concrete box walls crack and spall. Mortar joints between masonry units erode. Frames shift and grates become misaligned or corroded beyond their service life. Structural failures in a catch basin allow soil infiltration around the structure, which undermines the pavement above and can cause the basin to sink or collapse.

We repair concrete catch basin walls and joints using mortar patching and hydraulic cement for active infiltration conditions. We replace grates and frames where corrosion has reduced their structural integrity or where grate opening size does not meet current standards. Where a basin structure has failed beyond repair, we excavate and replace the full catch basin box and reconnect to the existing drain line.

Storm Drain Line Repair and Replacement

Storm drain pipe sections develop the same failure modes as sanitary sewer pipe: offset joints, cracks, root intrusions in older clay or concrete pipe, and collapsed sections in deteriorated material. The repair approach follows the same camera-first assessment used for sanitary line work. Where a trenchless method applies, we present it. Where direct excavation is required, we proceed with the same precise excavation to the failure point that we use on sanitary sewer repairs.

Storm drain pipe repair requires coordination with the property’s surface drainage pattern. A repaired line must be reconnected at the correct grade to ensure it continues to drain toward the outlet, not away from it. Re-grading consideration is part of every storm drain line repair scope.

Property Managers with Surface Parking

Apartment complexes, commercial office properties, and retail sites with surface parking lots generate significant stormwater runoff from large paved areas. Catch basins in high-traffic parking areas fill faster than basins in low-traffic zones because vehicle traffic continuously grinds aggregate off the asphalt surface and deposits it near drain inlets.

Property managers who add catch basin cleaning to their annual maintenance schedule alongside sewer line cleaning eliminate a significant source of property damage calls during summer thunderstorm season. The cost of annual catch basin maintenance is small relative to the cost of flood damage remediation after a major storm event overwhelms an unmaintained drain system.

Commercial Buildings and Retail Centers

Commercial buildings and retail centers with large rooftop drainage systems and surface parking require storm drain maintenance as part of routine property management. Roof drain leaders that connect to underground storm lines need the same periodic inspection and cleaning as parking lot catch basins. Sediment and organic material from roof surfaces accumulate in underground storm lines and restrict flow without any visible indication at the surface until a storm event overloads the restricted system.

Contractors and ADU Builders

New construction and ADU projects that add impervious surface area to a property may require storm drainage improvements as part of the Denver SUDP (Sewer Use and Drainage Permit) review process. We assess existing storm drainage infrastructure as part of the utility discovery and site evaluation work we perform for contractor clients and confirm whether the existing system has adequate capacity for the added surface area.

Step 3: Camera Inspection of Drain Lines (Where Requested or Indicated)

For properties with known drainage problems or no prior camera history, we scope the underground storm drain lines connecting the catch basins to their outlets. Camera footage documents pipe material, current condition, any blockages or structural failures, and the grade at each pipe segment.

Step 4: Drain Line Cleaning or Repair (Where Findings Indicate)

Where camera inspection shows restricted or blocked drain lines, we hydro jet the line and camera-verify the result. Where structural pipe failures are found, we present repair options with written pricing. Drain line repair follows the same camera-first, written-options process used on all other underground sewer work.

Step 5: Written Service Report

After service is complete, the property receives a written report documenting each catch basin serviced, the condition found, the work performed, and any findings requiring follow-up attention. On properties where camera inspection was performed, the camera footage is included. HOA boards use these records for maintenance logs, reserve fund documentation, and stormwater compliance files.

The storm sewer carries rain and snowmelt runoff from parking lots, rooftops, and other surfaces directly to waterways or detention ponds without any treatment. The sanitary sewer carries wastewater from toilets, sinks, and drains to the municipal treatment plant. In Denver, these are completely separate systems with separate underground networks. A blocked storm drain floods parking areas and building entries. A blocked sanitary sewer backs up inside building drains. The two systems need separate maintenance programs because their failure modes and consequences are different.

Most commercial catch basins need annual cleaning. Properties with high parking lot traffic, significant tree cover over paved areas, or sites adjacent to construction activity that generates sediment may need cleaning every six months. The best timing on the Front Range is late spring, after snowmelt season, so the system enters summer thunderstorm season with cleared capacity. Properties with known drainage problems benefit from inspection and cleaning before and after each major storm season.

The sump is the area at the bottom of the catch basin box, below the outlet pipe connection, that collects sediment and debris carried in by surface runoff. As stormwater flows through the inlet grate, it slows in the basin and heavy material settles to the bottom before the water flows out through the outlet. Over time, the sump fills with sediment, gravel, leaves, and pollutants. When the sump is full, material flows through to the drain line and accumulates in the underground pipe.

Yes. We camera-inspect storm drain lines using the same high-definition equipment used for sanitary sewer inspection. We may use robotic cameras to inspect larger diameter storm drains. Storm drain camera inspection shows pipe material, current condition, debris accumulation, root intrusions in older clay or concrete pipe, and any structural failures. We recommend scoping storm drain lines on properties that have never had the underground system inspected, on properties where surface flooding continues after catch basin cleaning, and before any storm drain repair work is planned.

Yes. Storm drain infrastructure on HOA-owned common property, including parking lots, driveways, and landscaped areas, is the HOA’s responsibility to maintain. Denver’s stormwater program holds property owners responsible for maintaining private storm drain infrastructure to prevent flooding, erosion, and illicit discharge to the city’s storm system. An HOA board that cannot document regular catch basin maintenance has a liability exposure both for property damage from flooding and for stormwater compliance review.

A full sump passes its accumulated material to the underground drain pipe. The drain pipe gradually restricts as material builds in the line. Flow capacity decreases. During a normal rain event, the drain cannot keep pace with inflow, the catch basin overtops at the grate, and surface flooding begins. On the Front Range, where summer thunderstorms generate high runoff intensities, an undermaintained drain system that handles light rain events may still fail catastrophically during a 1-inch-per-hour rain event. The cost of the resulting flooding, pavement damage, and landscape repair typically far exceeds the cost of annual maintenance.

Yes. If a catch basin is blocked or overflowing during or after a weather event, call 303-562-9800. We respond to storm drain emergencies affecting commercial properties and HOA communities. Properties that have already experienced flooding benefit from both the emergency service call and a scheduled follow-up inspection to assess whether the underlying cause is a sump that needs cleaning, a blocked drain line, or a structural issue in the catch basin or line.