Search Colorado Stormwater Permits, NPDES Records & Local Files
A Colorado stormwater permit search can involve several systems. The Colorado Department of Public Health and Environment administers most Clean Water Act discharge permits through the Colorado Discharge Permit System, while EPA ECHO provides national NPDES compliance data and cities may maintain separate erosion-control, grading and MS4 records.
Start with the permit number when you have it. For construction sites, numbers beginning with COR can identify Colorado construction stormwater certifications under the statewide COR400000 general permit. Then check the local jurisdiction because a state discharge authorization does not replace municipal erosion-control or grading requirements.
Where Should You Start a Colorado Stormwater Permit Search?
The correct database depends on what you are trying to verify. Colorado commonly uses the term Colorado Discharge Permit System (CDPS) for state-issued Clean Water Act discharge permits. Searchers may still use “NPDES” because CDPS operates within the federal National Pollutant Discharge Elimination System framework.
Colorado is an EPA-authorized NPDES state for most permit functions. That means many stormwater permits are issued and administered by the state rather than directly by EPA. EPA nevertheless remains important for national compliance records and for permit categories over which it retains authority.
| What you need | Best starting point | What to look for |
|---|---|---|
| Colorado construction stormwater permit | CDPHE / CDPS records and CEOS | COR permit number, facility, permittee, certification and coverage dates |
| NPDES compliance or enforcement history | EPA ECHO | NPDES ID, permit status, inspections, violations and enforcement data |
| Local erosion-control or grading approval | City, county or MS4 permit portal | Local permit number, project address, plans, inspections and closeout |
| Municipal MS4 permit records | Local stormwater program plus CDPHE/EPA | MS4 permit, program documents, annual reports and enforcement information |
| Older permit documents or correspondence | Colorado Environmental Records | Certification letters, reports, correspondence and archived permit material |
How to Search Colorado CDPS Stormwater Permit Records
The Colorado Department of Public Health and Environment’s Water Quality Control Division administers the Colorado Discharge Permit System. For permittees, consultants and applicants, Colorado Environmental Online Services (CEOS) is the state’s electronic permitting platform. It supports permit applications, amendments, renewals, terminations and other permit-related submissions.
For public research, Colorado also maintains an Environmental Records system. EPA’s review of Colorado’s NPDES program identifies the state’s OnBase environmental-records viewer as a public access point for Water Quality Control Division permit records. Depending on the permit and record age, available documents can include certification letters, reports and agency correspondence.
Collect a strong identifier
Use the exact permit or certification number if available. Otherwise gather the project name, legal permittee, facility name, city, county and approximate permit year.
Open the state record systems
Use Colorado Environmental Records ↗ to locate public documents. Applicants and permittees can also use Colorado Environmental Online Services ↗ for electronic permit activity.
Search narrowly first
Begin with the complete permit number. If that produces no result, try the facility or project name and then broader location details. A project may be indexed under the developer, contractor, public agency or another legal entity rather than the name used on a real-estate listing.
Open the underlying documents
Do not rely only on a search-result row. Review the permit certification, effective and expiration dates, modification history, termination information and correspondence where available.
Cross-check with EPA ECHO
Use the same permit or facility identifiers in EPA ECHO to see whether federal NPDES data contain additional permit, inspection, compliance or enforcement information.
Check the local jurisdiction
If the project is inside a regulated municipal stormwater area, search the city or county’s erosion-control, grading, development or stormwater records. Local requirements may apply in addition to state coverage.
How to Use EPA ECHO for Colorado NPDES Records
EPA’s Enforcement and Compliance History Online system is one of the most useful cross-checks for a Colorado stormwater permit search. Its Wastewater/Stormwater/Biosolids search draws from the federal ICIS-NPDES database and can display permit, inspection, compliance and enforcement information.
ECHO supports searches using facility names, NPDES IDs, state, county and other criteria. EPA also provides an Industrial Stormwater search and, as of 2026, search options for facilities covered under master general permits.
Search by NPDES or permit ID
This is the best method when a permit document or agency record already gives you a program identifier. Enter the full ID first before trying partial values.
Search by facility
Use the official facility name and Colorado as the state. Add county or city only when needed to distinguish similar names.
Review permit status
ECHO can show statuses such as effective, expired, administratively continued, pending, retired or terminated, depending on the source record.
Check compliance context
Where data are available, review inspections, reported noncompliance, enforcement actions and other Clean Water Act information rather than treating permit issuance as proof of current compliance.
Open EPA ECHO ↗ or review EPA’s NPDES State Program Authority information ↗ when you need to determine which agency administers a permit.
COR400000 Construction Stormwater Permit: What the Current Permit Requires
Colorado’s current statewide construction stormwater general permit is CDPS General Permit COR400000. The current permit became effective on April 1, 2024 and is scheduled to expire at midnight on March 31, 2029.
The permit generally applies to construction activity disturbing one acre or more and to smaller sites that are part of a larger common plan of development or sale meeting the applicable threshold. The Water Quality Control Division can also designate a discharge for stormwater permitting when it contributes to a water-quality violation or is a significant contributor of pollutants.
| Permit item | Current requirement or meaning |
|---|---|
| General permit | COR400000 — Stormwater Discharges Associated with Construction Activity |
| Current permit term | Effective April 1, 2024 through March 31, 2029 |
| Typical disturbance trigger | One acre or more, including qualifying smaller sites within a larger common plan of development or sale |
| Application timing | Complete electronic application generally must be submitted at least 10 days before construction begins |
| Coverage before work | Written notice that coverage was granted is generally required before construction activity begins, subject to the permit’s emergency provisions |
| Owner/operator | The current permit establishes owner and operator responsibilities and generally requires both to agree to permit terms and sign the application when they are separate parties |
| Stormwater plan | A Stormwater Management Plan must be developed, implemented and maintained for covered construction activity |
| Routine inspection option | At least once every 7 calendar days, or at least every 14 calendar days with qualifying post-storm inspections within 24 hours after precipitation or snowmelt causing surface erosion |
| Outstanding Waters | Sites discharging to designated Outstanding Waters are subject to at least one inspection every 7 calendar days |
The permit also requires the Stormwater Management Plan to remain current as site conditions change. Plans must identify the Qualified Stormwater Manager, relevant permits, site conditions, pollutant sources, control measures and other required elements.
Construction permit records are especially useful when you are trying to verify whether a project had state stormwater coverage, which entity was listed as the permittee, the acreage identified in the application and whether the record has been modified or terminated.
For the governing permit and current guidance, use CDPHE’s COR400000 construction stormwater page ↗. Colorado’s underlying discharge-permit rules are published through the Colorado Secretary of State Regulation No. 61 page ↗.
Why Local Stormwater and MS4 Records Matter
A state CDPS permit is only one layer of stormwater regulation. Colorado municipalities and other operators of municipal separate storm sewer systems, commonly called MS4s, can impose local erosion-control, grading, drainage and stormwater-management requirements.
The current COR400000 permit expressly recognizes local authority. Permittees must comply with lawful requirements of municipalities, counties, drainage districts and other agencies, including applicable erosion and sediment-control rules.
That is why a complete search may require both the state record and the local development file.
City of Boulder
Boulder requires an Erosion Control Permit for projects disturbing one acre or more, projects within a larger qualifying common plan, and certain projects the city expects to exceed the threshold. Its submittal requirements include a Stormwater Management Plan and a copy of the applicable Colorado construction stormwater general permit certification.
Boulder public records
The city’s Planning & Development Services records resources point users to its Customer Self-Service portal, property information and open-data tools. Available records can include permit descriptions, project numbers and inspection information.
Denver
Denver uses local erosion-control and drainage permitting in addition to state requirements. City documents refer to a Construction Activities Stormwater Discharge Permit, also described as an erosion-control permit, for projects where local criteria require it.
Colorado Springs
Colorado Springs Stormwater Enterprise administers local stormwater design and construction requirements. Its Stormwater Construction Manual addresses grading and erosion-control permitting, construction-phase requirements, inspections and permit closeout.
What is an MS4 permit?
An MS4 permit regulates stormwater discharged through a publicly operated separate storm sewer system. The permit holder is usually a municipality, transportation agency or other public entity, not the homeowner or developer researching a construction site.
However, an MS4 permit normally requires the public entity to maintain programs for construction-site runoff, illicit discharges, public education and other stormwater controls. Those local programs can create permits, plan-review files, inspection records and enforcement records that are useful when researching a particular site.
For example, Colorado Springs identifies its municipal MS4 permit as COS000004 and publishes MS4 materials through its Stormwater Enterprise. Local files should be read alongside—not instead of—the state construction stormwater record.
How to Search by Permit Number, Facility, Address or Owner
Search by permit number
A known permit number is usually the most precise identifier. Copy the complete number from a certification letter, site notice, engineering report, environmental file or agency correspondence. Search it without adding an owner name or date at first.
If the number does not return a match, check whether it belongs to a local permit rather than the state CDPS program. Local grading, erosion-control and drainage permits can use completely different numbering systems.
Search by facility or project name
Try the legal project or facility name appearing on agency documents. A subdivision may be recorded under a development name, while the state permittee could be a limited-liability company or contractor.
Search variants carefully. Do not assume a marketing name, HOA name and legal permittee name are interchangeable.
Search by address
Address searches are especially useful in local municipal systems. State environmental records may be indexed by facility, permit number or permittee rather than by a residential-style street address.
For vacant land, road projects, subdivisions and linear infrastructure, an ordinary street address may be incomplete. Use county, project name, parcel information or permit identifiers to narrow the search.
Search by owner or operator
The current COR400000 permit distinguishes owner and operator responsibilities. A developer may own the project while a contractor has operational control over construction activities. Search both names when researching current or historical coverage.
- Exact permit or certification number
- Project or subdivision name
- Legal owner or permittee
- Construction operator or contractor
- Street address when available
- City and county
- Approximate application or construction year
- Known local grading or erosion-control number
What Does a Colorado Stormwater Permit Record Tell You?
A permit search can confirm useful facts, but the meaning depends on the record type. Review the complete file before drawing conclusions about compliance or project status.
| Record field | What it helps verify | What it does not prove |
|---|---|---|
| Permit / certification number | Identifies the specific regulatory record | That every local approval was obtained |
| Permittee or operator | Who was associated with the state permit record | Current property ownership |
| Effective date | When permit coverage became effective | That construction actually began on that date |
| Expiration date | Permit term or coverage framework | That a site was properly terminated or closed |
| Termination | That coverage was ended in the agency system | That unrelated permits or enforcement matters are closed |
| Inspection or enforcement history | Recorded agency activity and compliance events | Absence of an issue that was never inspected or entered |
Effective does not mean “fully compliant”
An effective permit means the authorization is within its applicable term or status. It does not certify that every inspection passed, every control measure was maintained or every local requirement was satisfied.
Terminated does not erase history
A terminated construction stormwater certification may be exactly what you expect after final stabilization and proper closeout. Historical inspection, correspondence or enforcement records can still remain relevant to due diligence.
No result does not prove no permit existed
Records can be split among state, federal and local systems. Older documents may be indexed differently, and project names may have changed. If the project should reasonably have generated a record, broaden the search before concluding that no permit exists.
Colorado Stormwater Permit Search Not Finding the Record?
| Problem | What to try next |
|---|---|
| Exact permit number returns nothing | Check punctuation, distinguish state versus local numbering, then search the facility name in Colorado Environmental Records and EPA ECHO. |
| Address search fails | Use project, subdivision, facility, permittee or parcel information. Large sites may not be indexed under a conventional street address. |
| State record exists but no local file appears | Confirm municipal jurisdiction and search local grading, erosion-control, drainage, engineering or development records. |
| Local permit exists but no COR record appears | Check project acreage, larger common-plan status, qualifying local program rules and whether state coverage was required for that specific activity. |
| Permit appears expired | Look for renewal, administrative continuation, replacement, transfer, termination or subsequent certification records before interpreting the status. |
| EPA and state information differ | Compare identifiers, data dates and the actual state permit documents. Contact the responsible agency when a consequential discrepancy remains. |
If you are reviewing a property transaction, construction dispute or potential violation, save the permit number, source URL, date checked and relevant official documents. When the issue could affect legal rights, environmental liability or construction authorization, obtain advice from the appropriate agency or qualified professional.
Which Records Should Different Searchers Check?
Property buyers
Compare visible site improvements with local development permits, grading records and any state stormwater records associated with recent major construction. A former construction permit does not by itself identify every current maintenance obligation.
Developers and contractors
Confirm whether state construction stormwater coverage and local erosion-control or grading approvals are both required. Use current agency guidance before land disturbance begins.
Neighbors and community researchers
Search the state permit record, EPA ECHO and the municipality’s stormwater or planning files. If runoff or an illicit discharge is occurring now, use the responsible local or state reporting channel rather than relying only on historical records.
Environmental consultants
Cross-reference permit certifications with the project’s Stormwater Management Plan, inspection records, receiving-water information, local MS4 requirements and any related dewatering or discharge authorizations.
Colorado Stormwater Permit Search FAQs
1. Where can I search Colorado stormwater permits?
Start with CDPHE’s Water Quality Control Division resources, Colorado Environmental Records and CEOS. EPA ECHO is useful for NPDES permit and compliance data. Also search the local city or county when you need erosion-control, grading or MS4 records.
2. Is a Colorado CDPS permit the same as an NPDES permit?
CDPS is Colorado’s state discharge-permit program operating under the Clean Water Act NPDES framework. Colorado has EPA authorization for major NPDES program components, so state-issued CDPS permits commonly serve the function searchers associate with an NPDES permit.
3. What is COR400000?
COR400000 is Colorado’s general permit for stormwater discharges associated with construction activity. The current permit term runs from April 1, 2024 through March 31, 2029.
4. When is a Colorado construction stormwater permit generally required?
The statewide construction permit generally applies to projects disturbing at least one acre and to qualifying smaller sites that are part of a larger common plan of development or sale. CDPHE can also designate certain discharges for coverage. Local requirements may be broader or additional.
5. Can I search a stormwater permit by property address?
Sometimes. Local municipal systems commonly support address searches, while state environmental records may work better with a permit number, project name, facility name or permittee. For subdivisions and large sites, an address-only search can miss the record.
6. Does EPA ECHO show Colorado stormwater permits?
ECHO contains Clean Water Act information drawn from ICIS-NPDES and can show Colorado permit identifiers, statuses, compliance information and related records where the data are available. It is a useful cross-check rather than a replacement for the underlying state permit file.
7. Do I need to check local stormwater permits too?
Yes when local requirements apply. Cities, counties and other MS4 operators can require erosion-control, grading, drainage or construction-stormwater approvals in addition to state CDPS coverage.
8. What does an effective stormwater permit status mean?
It generally indicates the permit or coverage is within its active regulatory period according to the source system. It does not guarantee that the permittee is currently complying with every permit condition or that the project has completed all local approvals.
9. Why can’t I find an older Colorado stormwater permit?
Older records may be archived, indexed under a former permittee or project name, or divided between state and local systems. Try the permit number, former developer, facility name, location and approximate year, then request records from the responsible agency if needed.
10. Does a stormwater permit replace a building or grading permit?
No. A state stormwater discharge authorization addresses regulated discharges. Building, zoning, grading, floodplain, right-of-way and other approvals can be separate and may be administered by different agencies.
Use the Official Record That Matches Your Question
If you already know the permit number, search the Colorado environmental record first, then cross-check it in EPA ECHO. If you are researching a construction site by location, identify the municipality or county and look for a local erosion-control, grading or development permit as well.
For a current construction project, verify requirements before disturbing land. COR400000 requires covered applicants to follow the state application and Stormwater Management Plan requirements, while local jurisdictions may impose additional standards.
For an older property or completed development, focus on the record trail: certification, permit dates, modifications, termination, local closeout and available inspection or enforcement information. Save the underlying agency documents rather than relying on a search-result summary alone.