HomeMy WebLinkAboutFlowing Well Park variance analysis.pdfFlowing Well Park
Variances to Chapter 10, Article 5 of the Carmel City Code – Carmel Flood Hazard Areas Ordinance.
Site and Building Metrics
The proposed restroom building is located in the floodway fringe within Zone AE per FEMA FIRM Map
Panel 18057C0227G, dated 11/19/2014.
Base flood elevation (BFE) = 747.8’ (all elevations are NAVD 88 datum)
Flood protective grade (FPG) = 749.8’ (BFE + 2 ft)
Finish floor elevation (FFE) of proposed building = 744.6’
Use of proposed building: 2 restrooms with mechanical room for a municipal park
Gross square footage of building = 224 sq.ft.
Foundation system of proposed building: concrete footings, concrete slab on grade.
Construction system of proposed building: concrete masonry units with architectural exterior finish,
wood rafter framing and decking for roof.
Analysis of Variances
Ordinance Ch. 5 (B) (7) – Accessory Structures
1. The proposed building is classified as an “Accessory Structure”.
2. Subparagraphs (a), (b), (c), and (d) are satisfied by the current design. No variance required.
3. Subparagraph (f) is satisfied by providing 2-way flood vents into each restroom space. No
variance required.
4. A variance will be required for subparagraph (e) due to a conflict with the electrical code for
height of electrical panel above the floor. By code, the uppermost circuit breaker cannot be
higher than 6.5’ above FFE. Setting the bottom of the 200A, 30-circuit panelboard at FPG would
result in the uppermost breaker being approximately 7.7’ above FFE. The proposed design sets
the bottom of the proposed electrical panel at 3.3’ above FFE or at an elevation of 747.9’. The
electrical panelboard will be above the BFE but not above the FPG. All other mechanical
equipment is located above the FPG or is floodproofed against damages due to inundation.
Ordinance Ch. 5 (A) – General Standards
1. Paragraphs (1) through (4) and (6) though (9) are satisfied by the current design. No variance
required.
2. A variance will be required for Paragraph (5) for the same reason as Ch. 5 (B) (7) (e) above.
3. A variance will be required for Paragraph (10) – “Parking lots, driveways, and sidewalks within
the SFHA shall be constructed with permeable materials”. The existing parking lot, driveway,
and sidewalks, much of which will remain in place, are not currently permeable pavement
systems. The new sidewalks and the parking lot expansion are not proposed to be constructed
using permeable pavement systems. The application of permeable pavement systems within an
SFHA does not reduce the BFE. Expensive cleaning and maintenance of the permeable
pavement systems located in a SFHA after each flooding event is required so that the
permeability of those systems is not significantly reduced due to flood sedimentation.
4. Paragraph (11) is satisfied by the current design. No variance required. Fill is not required for
the proposed building. The FFE of the proposed building is below the current ground elevation
at that location due to ADA accessibility requirements from adjacent pavements. Fill is required
for a portion of the parking lot expansion and for the sidewalk leading into the site from 116th
Street. However, these fills are more than compensated for and balanced by the streambank
stabilization activities along the adjacent sections of Cool Creek.
Ordinance Ch. 5 (B) – Specific Standards
1. The gross floor area of the proposed building is less than 400 sq.ft., therefore the provisions of
Paragraphs (1) through (6) and (8) do not apply to the subject project. The provisions of
Paragraph (7) may apply as discussed above.
Summary of Variances Requested
1. Ordinance Ch. 5 (A) (11) - variance to allow non-permeable pavement systems in SFHA.
2. Ordinance Ch. 5 (B) (7) (e) - variance to allow electrical panel to be lower than FPG but above
BFE.