Stormwater Maintenance

Storm Sewer Maintenance Section

The Storm Sewer Maintenance Section (closed system) handles the operation and maintenance of the City's storm sewer system including tasks such as inspecting, cleaning, and repairing manholes, inlets, and storm sewer lines.
This section operates and maintains the following assets over a 650 square mile region:

  • Approximately 3,900 Miles of Storm Sewer Lines 
  • Approximately 250,000 of related infrastructure (manholes, inlets, other)
  • 6,305 Outfalls
  • 33 Roadway Underpasses with Storm Ponding Level Warning Devices (14 with Pump Stations)

This Section is also responsible for entering large-diameter storm sewers to remove debris and objects that can block the storm sewer. These tasks are performed by "Confined Space Entry" teams that ensure safe maintenance in these conditions. The Section also conducts inspections of new and rehabilitated storm water systems. 
By design, storm sewers are self-cleaning; however, these sewers are designed only for storm water and empty directly into major ditches and bayous. To limit environmental concerns and maintenance needs, citizens should never dispose of grass clippings, motor oil, or any other items/debris in the storm sewer.

Ditch Maintenance Section
The Ditch Maintenance Section (open system) handles the operation and maintenance of the City's ditches (roadside and major/off-road) and detention systems which includes tasks such as de-silting and re-grading ditches, as well as flushing culverts under driveways and streets.
To ensure routine daily activities can be carried out, this section operates and maintains the following assets over a 650 square mile region:

  • Approximately 2,500 Miles of Roadside Ditches (Both Sides of Street)
  • 100 Miles of Off-Road/Major Drainage Ditches
  • 35 Storm Water Detention Basins

Ditch standing water (ponding) is to be expected in some cases and should not have a negative impact on operability as long as the ditch provides positive drainage during normal rainy conditions. Standing water is typically caused by driveway culverts of various sizes and offsets either not installed at the optimum ditch flow line or due to soil movement (attributable to changing moisture conditions).
Per City Code of Ordinance, it is the abutting property owner’s responsibility to maintain ditches free of debris so water can flow with minimal obstructions (clear of weeds, brush, rubbish, or any debris that may prevent the flow of water). SWOB re-grades ditches that become heavily silted. Culverts are also flushed during this activity. On the other hand, new culverts, or culverts that are damaged or undersized below residential or commercial driveways, are the property owner's responsibility for replacement. Property owners have the option to make repairs to the driveway and its culvert; however, this requires all parties involved to coordinate with the City through the permitting system. Many off-road/major drainage ditches are also cleaned and re-graded by the Section. These off-road ditches collect storm water from many smaller ditches and storm sewers and transport it to larger ditches and/or bayous maintained by the Harris County Flood Control District.

A Roadside Ditch Re-establishment Program has been created to provide a best value proactive approach to Houston by progressively transitioning from 311-only reactive operations to a planned-work methodology to inspect roadside ditches citywide and re-establish those in non-functional condition. The Program starting fiscal year 2024 gives priority to areas with most ditches in need of improvements and sets a path to a full transition by fiscal year 2028. The Program does not alter the current basic maintenance responsibilities by abutting property owners. See Program details at:

Vegetation Management Section
The Vegetation Management Section maintains the green spaces in the City’s right-of-way (behind curb line), off-road channels, and drainage easements by properly controlling it in an environmentally sensitive and uniform manner while prioritizing safety considerations and drainage functionality. This Section also inspects and maintains green stormwater infrastructure (GSI) applications located in the City’s right-of-way while coordinating with technical and specialized internal and contracted services. The green areas maintained by the Vegetation Management Section are structured in 12 “green zones” that have similar acreage and are mowed on an even one-to-two times a year cycle citywide based on available resources. Click to see City’s Green Zone Map here.