Detention and retention are both used to manage stormwater, but they are not interchangeable. The right approach depends on the drainage design, site conditions, public requirements and long-term maintenance plan.
In simple terms, a detention facility temporarily holds runoff and releases it at a controlled rate.
A retention facility is designed to capture and retain stormwater, often using infiltration, a permanent pool or another approved approach. The specific design, outlet structure, water-quality features and maintenance obligations come from the approved drainage documents—not from the name of the pond alone.
Why the distinction matters on a Colorado Springs project
Development changes how rain and snowmelt move across a site. Roofs, pavement, compacted areas and new grades can increase runoff and move it faster. Permanent stormwater infrastructure is designed to manage that water in a way that protects property, downstream systems and receiving waterways.
Colorado Springs’ stormwater criteria cover public and private stormwater infrastructure, including underground conveyance, water-quality treatment and detention. The city’s code also requires a four-step process for new or redevelopment projects that disturb one acre or more, or are part of a larger common plan that does.
That process addresses runoff reduction, water-quality capture, drainageway stabilization and long-term source controls.
This means stormwater is not simply a final grading item. It is a coordinated civil scope that affects land planning, utility layout, site elevations, access, erosion control and future maintenance.
Typical components that need to work together
A permanent stormwater system can include more than a basin. Depending on the approved plan, the work may involve inlets, storm sewer, manholes, culverts, channels, outlet structures, swales, water-quality features, detention or retention storage, access routes and erosion protection.
The construction sequence matters. Storm pipe and structures need the correct line and grade. Basin excavation must match the approved elevations and geometry. Outlet controls, underdrains and stabilization features must be installed as designed.
Finished grades need to direct runoff to the intended collection points—not create a bypass around them.
A stormwater question is also a long-term operations question
The owner’s responsibility does not end at construction closeout. Colorado Springs’ criteria include permanent-control measures and maintenance concepts because stormwater infrastructure must continue working after the contractor leaves the site. The team should clarify who will own, inspect and maintain each feature before final acceptance.
This is especially important for developments with shared infrastructure, private drainage facilities, commercial properties or public dedications. A facility that is difficult to access or does not match the approved documents can create a lasting operations problem.
Bring the civil contractor into the drainage conversation early
The civil contractor helps turn the drainage report into field work that can be built, inspected and maintained. That includes coordinating earthwork, utility crossings, storm structures, erosion control, access and the work sequence.
633’s civil construction services and site utilities services bring grading, storm drainage and underground infrastructure together. For owners deciding between site concepts or moving an approved drainage plan toward construction, contact 633 Construction to review the civil scope before field work begins.
