Permit Review Detail
Review Status: Completed
Review Details: FLOODPLAIN
Permit Number - T08OT02278
Review Name: FLOODPLAIN
Review Status: Completed
| Review Date | Reviewer's Name | Type of Review | Description | Status | Comments |
|---|---|---|---|---|---|
| 12/08/2008 | JASON GREEN | ENGINEERING | REVIEW | Denied | DATE: December 8, 2008 SUBJECT: 8750 E Woodland Road Barn Additions- 2nd Engineering Review TO: Platosa LLC LOCATION: T13S R15E Sec34 and T14S R15E Sec03, Ward 2 REVIEWERS: Jason Green, CFM ACTIVITY: T08CM03103, T08CM03104 (Site Plans) and T08OT02278 (Floodplain Use Permit) SUMMARY: Engineering Division of Development Services Department has received and reviewed the revised Site Plan applications (T08CM03103 and 03104), Floodplain Use Permit (T08OT02278), Drainage Report (Richard G. Macias, 14NOV078) and Elevation Certificate (Putt Land Surveying, Inc., 24NOV08) for the above referenced property and does not recommend approval of the Site Plans, Floodplain Use Permit or Drainage Report at this time. The subject property is fully located within the Floodway of the Tanque Verde Creek and within a Special Flood Hazard Area (SFHA), Zone AE as shown on the Flood Insurance Rate Map (FIRM), Community- Panel No. 040073-04019C-1670K, effective date July 24, 2000. The following information is required: FUP SITE PLAN: 1) Restated: TC Sec.26-11.2.2.e: Provide a revised engineering study prepared by a state-registered professional civil engineer outlining the effects the development will have on the flow of water through the area being developed and the surrounding areas. The Drainage Report submitted does not accurately reflect the encroachments proposed per the submitted site plan. The study must accurately evaluate possible flood hazards and shall, where necessary, include consideration of the effects of the development on flood heights, water velocities, direction of flow, sedimentation and/or erosion, volume of flows, channel shape and size, type of channel banks and other items that may be pertinent, and the resultant effects or structures, land, banks, etc., for the adjacent regulatory floodplain and the surrounding area. 2) Restated: TC Sec.26-5: Revise the engineering study to accurately address all of the requirements outlined in sections 26-5.1 and 26-5.2 below. Areas designated as floodways have a high potential for flooding. Land in the floodway should be set aside for the conveyance of floodwaters as a first priority. Floodways are also areas of major groundwater recharge, a characteristic which should be preserved and enhanced where possible. Sec.26-5.1- Development in the floodway shall: a) Conform to adopted city land use plans for the design of public and private development in the floodplain. This comment was not fully addresses. The HEC-RAS model submitted does not reflect the proposed encroachment within the cross sections. The existing and proposed sections are the same and do not show the placement of fill, barns, stalls, sheds, water tanks, etc. b) Not result in damage to public facilities as a result of erosion or flooding events. This comment was not fully addresses. The HEC-RAS model submitted does not reflect the proposed encroachment within the cross sections. c) Not generate adverse impacts (including but not limited to erosion) upstream or downstream. This has not been addresses since the HEC-RAS model does not show the proposed encroachment within the section. d) Not unnecessarily alter riparian habitats of watercourses and adjacent bank areas. This comment has not been fully addressed. The proposed improvements and additional disturbance within a regulated 100-year floodplain and Environmental Resource Zone area is causing unnecessary disturbance to the regulated riparian habitat per DS Sec.9-06 and TC Chapter 29. Per the meeting discussion on Friday, 05DEC08, Joe Linville provided 2 exceptions to this Standard, verify conformance with the exception or provide an ERR. e) Not increase the base flood elevations. Per FEMA, the Code of Federal Regulations (Title 44) and the City of Tucson Floodplain regulations this means zero rise in the WSEL. A No-Rise Certification from a state-registered professional civil engineer will be required. This comment was not fully addresses. The HEC-RAS model submitted does not reflect the proposed encroachment within the cross sections. f) Not result in higher floodwater velocities which significantly increase the potential for flood or erosion damage. This comment was not fully addresses. The HEC-RAS model submitted does not reflect the proposed encroachment within the cross sections. g) Not significantly increase channel or bank erosion. This comment was not fully addresses. The HEC-RAS model submitted does not reflect the proposed encroachment within the cross sections. h) Not decrease groundwater recharge. This comment was not fully addresses within the report. i) Not contain a waste disposal system wholly or partially. Complied. j) Not result in the placement of any structure or material that may divert, retard or obstruct the flow of floodwaters. This comment was not fully addresses. The HEC-RAS model submitted does not reflect the proposed encroachment within the cross sections. k) Not result in creating a danger or hazard to life or property. This comment was not fully addresses. The HEC-RAS model submitted does not reflect the proposed encroachment within the cross sections. l) Not utilize structures except hydraulic structures and those structures exempted under section 26-4(4)--(8), which are designed and constructed to protect life or property from dangers or hazards of floodwaters. This comment was not fully addresses. The HEC-RAS model submitted does not reflect the proposed encroachment within the cross sections. m) Not contribute to debris accumulation upstream and/or downstream. This comment was not fully addresses. The HEC-RAS model submitted does not reflect the proposed encroachment within the cross sections. n) Not create a water pollution problem in the floodway due to soluble, insoluble, or solid materials, at the time of flooding. This comment was not fully addresses. The proposed improvements are for a horse stable and barn that will have waste (manure) sites and collection areas. Clarify how the manure will not create a water pollution problem within the floodway. Sec.26-5.2- Development in the floodway fringe shall: a) Conform to adopted city land use plans for the design of public and private development in the floodplain. This comment was not fully addresses. The HEC-RAS model submitted does not reflect the proposed encroachment within the cross sections. The existing and proposed sections are the same and do not show the placement of fill, barns, stalls, sheds, water tanks, etc. b) Not result in damage to public facilities as a result of erosion or flooding events. This comment was not fully addresses. The HEC-RAS model submitted does not reflect the proposed encroachment within the cross sections c) Not generate adverse impacts, including but not limited to erosion, upstream or downstream. This comment was not fully addresses. The HEC-RAS model submitted does not reflect the proposed encroachment within the cross sections d) Not unnecessarily alter riparian habitats of watercourse and adjacent bank areas. This comment has not been fully addressed. The proposed improvements and additional disturbance within a regulated 100-year floodplain and Environmental Resource Zone area is causing unnecessary disturbance to the regulated riparian habitat per DS Sec.9-06 and TC Chapter 29. e) Not increase the base flood elevation more than one-tenth of a foot. This comment was not fully addresses. The HEC-RAS model submitted does not reflect the proposed encroachment within the cross sections f) Not result in higher floodwater velocities which significantly increase the potential for flood or erosion damage. This comment was not fully addresses. The HEC-RAS model submitted does not reflect the proposed encroachment within the cross sections g) Not significantly increase channel or bank erosion. This comment was not fully addresses. The HEC-RAS model submitted does not reflect the proposed encroachment within the cross sections h) Use, where appropriate, native and/or adaptive landscaping to enhance the open space character of the floodway fringe. This comment was not fully addresses. The HEC-RAS model submitted does not reflect the proposed encroachment within the cross sections i) Place the first (including basement) floor one (1) foot above the base flood elevation. Following the pouring of the first slab or finish floor installation and prior to any framing, the applicant shall submit to the city engineer certification by state-registered land surveyor or a state-registered professional civil engineer that the elevation of the lowest floor is in compliance with that approved by the city engineer's office. This comment was not fully addresses. The HEC-RAS model submitted does not reflect the proposed encroachment within the cross sections and does not provide a cross section showing how the structure is elevated on fill or how the fill is protected from erosion j) Anchor all structures, material or equipment firmly to prevent their flotation. This comment was not fully addressed. The site plan does not show how the proposed 2-5,000 gallon water tanks are to be anchored to prevent floatation. k) Place all service facilities such as electrical and heating equipment at or above the regulatory flood elevation. This comment was not fully addresses. Clarify if the proposed water tanks will have electrical equipment associated with it. l) Be constructed so as to protect placed fill from erosion which could be caused by waters, or otherwise. Such fill shall be permitted only when demonstrated by the owner/developer that it will have some beneficial purpose, as determined by the city engineer, and the amount of proposed fill is not in excess of what is necessary to achieve that purpose. The fill shall be protected from erosion which could be accomplished by placing riprap, vegetative cover, bulk heading, or any other city engineer approved methods. This comment was not fully addresses. The HEC-RAS model submitted does not reflect the proposed encroachment within the cross sections and does not provide a cross section showing how the structure is elevated on fill or how the fill is protected from erosion. Provide all calculations for rock rip rap or erosion protection for the fill pad if it's not in conformance with TC Chapter 26 Section 26-8.d.2. m) Prohibit storage and/or processing of materials that are buoyant, flammable, explosive or that could be injurious to human, animal or plant life at the time of flooding. This comment was not fully addressed. The site plan does not show how the proposed 2-5,000 gallon water tanks are to be anchored to prevent floatation. n) Locate on-site sanitary waste disposal systems to avoid impairment to them or contamination from them during flooding. Complied. o) Locate water supply, water treatment and sewage collection and disposal systems to eliminate or minimize infiltration of floodwaters into these systems and discharge of materials from these systems into floodwaters. This comment was not fully addressed. The site plan does propose 2-5,000 gallon water tanks (water supply) and does not address how these systems eliminate or minimize infiltration of floodwaters. 3) Restated: TC Sec.26-7: Revise the engineering study to address the required erosion hazard setback (EHSB) from the Tanque Verde Creek (a Regional Water Course). Guidelines for such studies and for determining setbacks are found in the DS Sec.10-02.7.6 Standards Manual for Drainage Design and Floodplain Management in Tucson, Arizona (Standards Manual). The discussion in Section 4.4 of the Drainage Report and the proposed 50-foot EHSB does not satisfy the requirements for setbacks from a Regional Water Course without supporting calculations per the referenced Development Standard. 4) Complied. 5) Restated: The submitted Elevation Certificates for Buildings "D" and "E" that were required per the conditions under the Amended Floodplain Use Permit #502 for the construction of additions to the existing structure located in the FW of the Tanque Verde Creek shows that both additions are in violation of the amended FUP application and the City of Tucson Floodplain Ordinance (Tucson Code Chapter 26). Conformance with all past permits must be shown prior to approval of any new structure within the FEMA Floodway. Provide additional information that shows the finished floor elevation of the permitted additions elevated to the required height or provide a demolition permit that removes the structures from the existing non-conforming house so that it is in compliance with the local, state and federal regulations and guidelines for floodplain management purposes. 6) Restated: Be advised that all future improvements (walls, fences, pool, and detached or attached accessory structures) will require a separate permit and a Hydrology Report for review and approval. NEW COMMENTS 2nd REVIEW: 7) DS Sec.9-06 Refer to this section for the definitions, preparation, submittal, and review procedures for development within areas that have environmental habitat, Floodplain and Erosion Hazard Area Regulations. Any disturbance of the riparian habitat will require an Environmental Resource Report (ERR) approval from DSD Landscaping prior to site plan approval. Or provide conformance with 1 of the 2 exceptions that was provided by Joe Linville, Landscaping Section that was provided to you on Friday, 05DEC08. 8) DS Sec.9-06.2.1: All site plans, development plans, Tentative Plats, plot plans or other plans providing for approval of development within property that includes any Regulated Area as defined in Development Standard 9-06.2.2 shall identify and delineate the Regulated Areas and the Protected Riparian Area. The Regulated Areas on this site are the existing 100-year floodplain limit. An Environmental Resource Zone (ERZ) Overlay application is required for this project. Contact Patricia Gehlen, 837-4919 or Patricia.Gehlen@tucsonaz.gov for further requirements on submittal of an ERZ application to the CDRC Section. Or provide conformance with 1 of the 2 exceptions that was provided by Joe Linville, Landscaping Section that was provided to you on Friday, 05DEC08. 9) DS Sec.9-06.2.5.B.2: All development within the Protected Riparian Area shall be reviewed to insure that there is no unnecessary disturbance of the riparian resources. Refer to this section on Development Restrictions and revise the plans as necessary. Necessary development shall include only the crossing of riparian habitats with roadways, bikeways, paved walkways and utilities as listed below where there is no viable alternate crossing available and the crossing is necessary for the reasonable development of the property. A written explanation as to why the development is necessary shall be submitted with the appropriate plans. The Drainage Report and site plan indicate that multiple disturbance site is proposed within the existing 100-year floodplain of the subject property. This is not consistent with the provisions for "necessary development". Or provide conformance with 1 of the 2 exceptions that was provided by Joe Linville, Landscaping Section that was provided to you on Friday, 05DEC08. 10) DS Sec.9-06.2.5.B: If the project proposes encroachment within the Regulated Areas, it shall conform to the following. a) Environmental Resource Report. Applicants are required to submit an Environmental Resource Report as defined in Sec. 6.2.5 of the LUC. The supporting material for preparation of the Environmental Resource Report is based on information from the Hydrologic Data and Wash Information maps on the Tucson Department of Transportation internet web site: The Critical and Sensitive Wildlife Habitat Map and Report, the Mayor and Council Interim Watercourse Improvement Policy and subsequent adopted policies, the Tucson Stormwater Management Study, the following Basin Management Plans: 1) West Branch, Santa Cruz; 2) Houghton East; 3) Este Wash; and 4) Arroyo Chico. The Tucson Stormwater Management Study, Phase II and field observation. An application may request that an element listed below be waived or that the report addresses only a specified area where a full report is not applicable to the proposed encroachment. DSD may grant such waivers where the elements or full report are not required by code. The Environmental Resource Report must include all items (a-x) within this section. 11) Revise the proposed Drainage Report based on the following comments: a) Revise the discussion in Section 2.1 to include verbiage that the Tanque Verde Wash is classified as an Environmental Resource Zone watercourse and will need an ERZ Overlay application along with an ERR to address any proposed disturbance. b) Revise the discussion in Section 2.2 to include all proposed improvements. Per the submitted site plan there are 5 separate improvements being proposed. 1) expansion of the existing riding arena; 2) Replacement of 2- 5,000 water tanks; 3) 4- 8'x12' storage sheds; 4) enclosed, elevated horse barn with fill pad; and 5) open horse stalls. Per the Drainage Report only # 4 and 5 are discussed, clarify. c) Revise Section 4.3 and the HEC-RAS model within the Drainage Report for the proposed conditions. The proposed Cross Section 50.098 does not show proposed conditions. The section is at the upstream end of the improvements however it does not show new stationing or elevations for the fill, barn, sheds, stalls, etc. The cross section associated with the HEC-RAS Section 50 shows an area that is blocked out, however the input section again does not show the encroachment with new stationing or elevations, clarify. d) Revise Section 4.3 to include the numerical value for the regulatory flood elevation (RFE) that is proposed for the finish floor elevation of the barn (verify that the site plan FFE call out matches the Drainage Report). If the barn is to be elevated on fill the top of the fill pad must be at or above the base flood elevation and the report must provide a section through the structure to clearly show how the pad and floor are elevated to the required RFE. The fill pad must meet all requirements within TC Chapter 26 Section 26-8.d.2. e) Revise Section 4.4 to address the required erosion hazard setback (EHSB) from the Tanque Verde Creek (a Regional Water Course). Guidelines for such studies and for determining setbacks are found in the DS Sec.10-02.7.6 Standards Manual for Drainage Design and Floodplain Management in Tucson, Arizona (Standards Manual). The discussion in Section 4.4 of the Drainage Report and the proposed 50-foot EHSB does not satisfy the requirements for setbacks from a Regional Water Course without supporting calculations per the referenced Development Standard. If photo documentation is being used for historical evidence of the channel bank meandering there needs to be a longer history than the 10-year photography. Provide aerial photography of the site as far back as possible (Pima County has aerial photographs as far back as 1940). f) Clarify in the HEC-RAS model under Section 50.098 (Proposed Conditions Page 5) the change in the Manning's n-value with the proposed encroachment. The Manning's n-value should not decrease with additional improvements in the Floodway, revise or provide a discussion that clearly shows why the n-value decreases in this situation. g) Clarify in the HEC-RAS model under Section 50.098 (Proposed Conditions Page 5) the change in the Top Width dimension from existing to propose. The proposed section decreases the channel top width by 5.85 feet, clarify how this happens. 12) Clarify on the proposed engineered site plan all proposed improvements versus existing improvements. Provide an application (Building or Site) for all new structures, water tanks, grading of riding area, storage sheds, feed bins, 3-inch Fire Department Standard Pipe, etc. Verify that all permits have been submitted for each proposed improvement. 13) DS Sec.2-02.2.1.A.5: Clarify the proposed lot lines as shown on the site plan. Verify any new lot line configurations or lot combinations. The 50-foot Rear Yard Setback, per the lot configuration shown on Mapguide, is not measured from the back property line of the subject property but from a Pima County owned property line, clarify or provide the warranty deed that shows this area dedicated to the subject property. All lot combinations or reconfigurations will require approval from the Zoning Section of the City of Tucson Development Services Department prior to site plan approval. GENERAL COMMENTS: Please provide the revised engineered site plan, Drainage Report, ERZ application, ERR and all associated details that address the comments provided above. For questions or to schedule a meeting I can be reached at 837-4929. Jason Green, CFM Senior Engineer Associate Engineering Division Development Services |
Final Status
| Task End Date | Reviewer's Name | Type of Review | Description |
|---|---|---|---|
| 01/15/2009 | THAUSER1 | OUT TO CUSTOMER | Completed |
| 01/15/2009 | SUE REEVES | REJECT SHELF | Completed |