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Floodplain Permitting & Templates

If you need additional guidance, please reach out on our contact us page and one of our floodplain staff will get back to you shortly. 

SEMSWA Jurisdiction: Within the City of Centennial and unincorporated Arapahoe County. 

What activities need a Floodplain Development Permit (FPDP)? FPDPs are required for all activities in the floodplain. 

  • FEMA defines development as “any man-made change to improved or un-improved real estate, including but not limited to buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations, or storage of equipment and materials.” 
Floodplain Development Permits (FPDP) Details: 

SEMSWA’s Floodplain Program issues Floodplain Development Permits (FPDPs) for projects in and around the 100-year floodplain within our service area. A FPDP must be approved before other local permits (e.g., building, street cut, right-of-way use, GESC, public improvements) can be issued and prior to any other development, use, or change of use of land located in the Floodplain. 

All activities, regardless of impact, need to be permitted. Even when it is apparent that there are no adverse impacts to the floodplain, a permit is required for administrative purposes to ensure that SEMSWA is aware of the activities within the floodplain and that they have been evaluated for compliance with Centennial and/or Arapahoe County requirements.  

Centennial and Arapahoe County Floodplain Regulations and Permitting Requirements follow Federal and State criteria and are authorized through both the City Land Development Code and the County Land Development Code and are described in detail in the SEMSWA Stormwater Management Manual and the Arapahoe County Stormwater Management Manual.

What are project impacts? 

Hydraulic modeling may be required to determine if the proposed project will cause an impact to the floodplain.

  • No impact means 0.00 ft rise in the Base Flood Elevation (BFE) and no additional width added to the floodplain. 
  • Impact is defined as any rise in the BFE and/or additional land added to the width of the floodplain. 
Floodplain Permitting Options: 
  1. Floodplain Development Permit (FPDP)
    1. No Impact FPDP for no impact projects - An Engineer’s Certification of No Impact is required for administrative purposes for FPDP with no floodplain impact. In some cases, hydraulic modeling could be required.
    2. Standard FPDP for projects with impacts to a floodplain
      1. If the impacts will occur to a FEMA floodplain, a Conditional Letter of Map Revision (CLOMR) must be submitted and approved by FEMA prior to approval of the FPDP.
      2. If the impacts will occur to a local floodplain, i.e., a FHAD floodplain or an area of approximately mapped flood hazard, a Floodplain Modification Study (FMS) must be submitted to and approved by SEMSWA prior to approval of the FPDP. The FMS is a project-specific study on floodplain impacts.
  2. Annual Floodplain Development Permit – special permit issued for a calendar year specifically for Utility Companies or Parks and Recreation Districts who have various projects within the floodplain (see annual permits page)
How to Report Illegal Floodplain Development: 

If you are concerned about buildings, sheds, or fences you see being built near waterways and known floodplains, please reach out to SEMSWA. 

  1. Call SEMSWA at 303-858-8844
  2. Contact us using the “Contact Us / Report a Problem”
What Forms do I Need? 
FPDP with no impactsFPDP with impacts to FHAD floodplainFPDP with impacts to FEMA floodplain - CLOMRAnnual FPDP
FPDP Application (City or County- see below)FPDP Application (City or County- see below)FPDP Application (City or County- see below)FPDP Application (City or County- see below)
City of Centennial Floodplain Development PermitCity of Centennial Floodplain Development PermitCity of Centennial Floodplain Development PermitAvailable to Utilities and Parks and Rec districts
Arapahoe County Floodplain Development PermitArapahoe County Floodplain Development PermitArapahoe County Floodplain Development PermitAvailable to Utilities and Parks and Rec districts
Engineer's Certification of No Impact 
Two template choices (see below)Floodplain Modification StudyCLOMR report
A) Detailed Floodplain (Zone AE with BFEs)
Engineers Floodplain Certification StatementEngineers Floodplain Certification Statement
B) Local Floodplain
Hydraulic ModelingHydraulic Modeling
Hydraulic Comparison TableHydraulic Comparison Table
FEMA MT-2 forms
Floodplain Permit Applications, Templates, and Checklists 

Arapahoe County Floodplain Development Permit Application

  1. Arapahoe County Floodplain Development Permit – To be used for all proposed projects located in the floodplain within Unincorporated Arapahoe County

City of Centennial Floodplain Development Permit Application

  1. City of Centennial Floodplain Development Permit – To be used for all proposed projects located in the floodplain within the City of Centennial

No Impact Letter Templates 

  1. Engineer’s Certification of No Impact Template (FEMA, PMR, or FHAD floodplains)
  2. Engineer’s Certification of No Impact (Approximate Floodplain) Template

CLOMR/LOMR templates

  1. Floodplain Modification Study and Conditional Letter of Map Revision (CLOMR) Checklist 
  2. Letter of Map Revision (LOMR) No CLOMR Checklist
  3. LOMR Following CLOMR Checklist
  4. LOMR As-Built Drawing Checklist
  5. Engineers Floodplain Certification Statement
  6. Hydraulic Comparison Table

FEMA MT-1 and MT-2 forms

  1. MT-1: The FEMA forms for individual property owners (LOMA, LOMR-F) are located at:   https://www.fema.gov/flood-maps/change-your-flood-zone/paper-application-forms/mt-1
  2. MT-2: The FEMA forms for larger Capital Improvement projects (CLOMR/LOMR) are located at:  https://www.fema.gov/flood-maps/change-your-flood-zone/paper-application-forms/mt-2