Denver Development Services is the front door for essentially every site-civil approval inside the City and County of Denver, but "get a Denver grading permit" is not a single-step process. A land-development project layers a city grading and erosion-control review, a separate storm drainage design review against Denver's own criteria, and a state construction stormwater permit that exists independently of anything the city issues. Missing that any one of the three is required — or assuming the city permit substitutes for the state one — is the most common way a Denver project stalls at inspection.
What permits does the City and County of Denver require for site grading?
Denver Development Services issues the core site-civil approvals for land development: a grading and erosion-control permit covering earthwork, cut/fill, and temporary BMPs during construction, and site development plan review covering the overall drainage, utility, and infrastructure design for the parcel. Both are required on essentially every land-disturbing project inside city limits, and grading permit issuance is generally tied to an approved, or sufficiently advanced, site development plan.
Does Denver require a separate stormwater permit from the state's COR400000?
Yes. Denver's grading and site development review is a city-level land-use approval; it does not substitute for the state construction stormwater permit. Any project disturbing one acre or more — or part of a larger common plan of development — still needs coverage under the CDPHE Construction General Permit COR400000, administered by the Water Quality Control Division, and must prepare a Stormwater Management Plan (SWMP), Colorado's term for the construction-phase stormwater document, before disturbing soil. See our CDPHE COR400000 guide for the state-permit mechanics, and the Colorado site-civil permitting guide for how the state and local layers fit together statewide.
What is Denver's storm drainage design criteria, and when does it apply?
Denver maintains its own storm drainage design criteria — the engineering standards Development Services reviews new site drainage systems against, covering minor and major storm design, detention sizing, water quality treatment, and outfall requirements. These criteria apply on essentially every land-development project that adds impervious area or alters existing drainage patterns, and they are distinct from — though related to — the erosion and sediment control BMPs documented in the construction-phase SWMP. An engineer designing detention or water quality facilities to Denver's criteria should not assume those facilities automatically satisfy CDPHE's construction-phase expectations, or the reverse — one is permanent post-construction infrastructure, the other is temporary construction-phase control.
Who reviews grading and erosion control plans in Denver?
Denver Development Services is the reviewing authority for grading and erosion-control plans submitted as part of a site development plan or building permit package. Larger or more complex sites — those with significant floodplain, drainageway, or public infrastructure involvement — may also route through Denver's engineering division for drainage report review. Coordinating early with Development Services on which review track applies, and whether a separate drainage report is required, avoids a plan bouncing between divisions mid-review.
How does a Denver grading permit differ from site development plan review?
The grading and erosion-control permit is narrower: it authorizes earthwork and requires temporary erosion and sediment control measures to be in place before disturbance begins. Site development plan review is broader — it's the mechanism through which Denver approves the overall civil design for a parcel, including grading, drainage, utilities, and access, ahead of infrastructure and building permits. In practice the two run in sequence: the site development plan establishes the approved design, and the grading permit authorizes construction to begin against it.
| Approval | Issuing Body | What It Covers |
|---|---|---|
| Site development plan review | Denver Development Services | Overall grading, drainage, utility, and access design for the parcel |
| Grading and erosion-control permit | Denver Development Services | Authorizes earthwork; requires temporary BMPs in place before disturbance |
| Storm drainage design review | Denver Development Services / engineering division | Detention sizing, water quality treatment, outfall design vs. city criteria |
| CDPS Construction General Permit COR400000 | CDPHE Water Quality Control Division | State construction stormwater coverage; requires a SWMP |
| CDOT State Highway Access Permit (where applicable) | CDOT | Connections to the state highway system |
How do I sequence Denver grading, drainage, and CDPHE stormwater permits?
The efficient order starts with the site development plan, since it establishes the drainage concept every other approval depends on. Once that design is far enough along, submit the CDPHE COR400000 permit application through Colorado's Environmental Online Services (CEOS) system in parallel with finalizing the city's grading and drainage plan sets — the SWMP draws directly on the approved grading and drainage design, so it's inefficient to write it before that design is settled. Permit coverage under COR400000 must be certified, and the SWMP must be complete and on site, before any soil disturbance begins; the city's grading permit is typically the last approval issued before mobilization, since it depends on both the site development plan and, in practice, confirmation that state stormwater coverage is in place.
Does Denver require on-site detention or water quality treatment?
Most Denver land-development projects that increase impervious area are required to provide detention and water quality treatment sized to the city's storm drainage design criteria, rather than discharging the full post-development flow directly to the public system. The specific detention volume, release rate, and water quality treatment approach depend on the site's drainage basin and existing downstream infrastructure, so this should be confirmed against the current criteria manual and any applicable drainage basin master plan early in design — retrofitting a facility into a site plan after grading is finalized is far more expensive than sizing for it up front.
Across all three approvals, the common thread is that Denver treats land development as a land-use decision first and a stormwater compliance question second — even though the state's COR400000 permit is entirely separate from, and indifferent to, the city's process. Engineers who treat the site development plan, the grading permit, and the state SWMP as three genuinely different documents — rather than trying to compress them into one — tend to move through Denver's review process with the fewest resubmittals.