Article 2. Permit Applications and Procedures

6.201.   Application Submission Requirements

In addition to the materials listed at Section 2.303, applications for a permit to engage in development in any designated floodplain natural hazard area shall be accompanied by the following information, maps, requirements and data in the number required by the Director:

(1)

A complete application form.

(2)

A plan certified by a professional engineer, registered in the State of Colorado, locating the proposed development with respect to the following:

(a)

The boundaries of the designated or regulated floodplain natural hazard area.

(b)

Descriptions of any construction activity which would affect the hydraulic capacity of the floodplain.

(c)

Section 404 of the Federal Clean Water Act permit, if applicable.

(3)

The following maps or drawings:

(a)

A map showing the stream and channel, the designated floodplain natural hazard area surrounding the channel, the area to be occupied or affected, in terms of altered stormwater runoff flows, by the proposed development and all available flood elevation studies, water surface elevations and base flood elevations.

(b)

A map with surface view showing elevations or contours of the ground, pertinent structures, fill or storage elevations, size location and spatial arrangement of all proposed and existing structures on the site, location and elevation of streets, water supply systems, sanitary facilities and soil types.

(c)

Drawings showing the profile of the bottom of the channel at the thalweg and the water surface profiles described in such Paragraph a., above. The elevations of fill and structures must be shown. The applicant shall submit the elevation (in relation to mean sea level) of the lowest floor, including the basement, of the structure and, where the lowest floor is below grade on one (1) or more sides, the elevation of the floor immediately above.

(4)

The applicant shall submit evidence that the applicant has made adequate coordination with upstream, downstream or adjacent persons or communities and organizations that might be adversely affected by any development, fill, encroachment or alteration or relocation of a watercourse, including but not limited to, the Fountain Creek Watershed, Flood Control, and Greenway District.

6.202.   Map Requirements

(1)

Verification shall be provided identifying the source of the topography and the date it was produced.

(2)

All maps required to be submitted with a permit application shall be of a scale sufficiently detailed to allow the Development Services Director and/or the Permit Authority to determine whether the proposed development and the topographic features of the land meet the requirements of these regulations. In no event shall the scale of these maps be less than one (1) inch equaling one hundred (100) feet.

(3)

All required maps shall show existing topographic contours at no greater than two (2) foot intervals.

(4)

All maps prepared by private contractors or consultants shall meet the following standards of accuracy: Ninety (90) percent of the contour lines must be within one-half (½) contour interval and the remaining contour lines must be within one (1) contour interval.

(5)

All maps submitted by an applicant seeking a permit to develop a specific site shall show existing (dash line) and finished (solid line) elevation contours of the site at an interval of no greater than one (1) foot within a designated flood hazard area.

6.203.   MDDP Report Requirements

(1)

Location and description of the proposed development stating the proposed land use acreage and adjacent features to the site.

(2)

Calculations for design peak flows from all off-site tributary areas

(3)

Calculations for design peak flows from all onsite contributing drainage areas

(4)

Discussion and analysis of existing downstream facilities with particular focus on facilities which will have inadequate capacity based on increase in runoff in terms of increase in peak flowrates, duration, and volume of runoff. Alternatives shall be identified for downstream improvements required to address potential impacts.

(5)

Discussion of drainage problems anticipated within the development and their solutions.

6.204.   Drawing Requirements.

(1)

All regulatory floodplain and proposed areas inundated by 100-year recurrence interval

(2)

Existing topography

(3)

Location and size of open channels, bridges, culverts, storm sewers, and ponding areas

(4)

Identify all drainage areas/basins tributary to the development

(5)

Identify drainage sub-basins within the proposed development

(6)

Location of all proposed streets/highways classified as arterials or greater

(7)

Drawing scale shall be between 1"=50' to 1"=500"

6.205.   Review Criteria

A permit to engage in development in or affecting a designated floodplain natural hazard area shall be approved if the Permit Authority, or, in the case of an Administratively Approved Permit, the Director, finds the application complies with the following criteria and the relevant criteria at Section 2.405. If the Permit Authority or the Director, as appropriate, finds the application does not comply, the application shall be denied or may be approved with conditions.

(1)

Adequate mitigation measures have been proposed, including financial security to guarantee the same, to mitigate the following:

(a)

Detention and/or retention of storm water;

(b)

Erosion and sediment control for any development related land disturbance or construction;

(c)

Any necessary measures including channel protection and engineered outfalls;

(d)

Water quality controls, including water quality capture volume and determination of the need for temporary and/or permanent best management practices (BMP); and

(e)

Adequate provision for maintenance of all drainage-related facilities required by the development.