A. In any case where development is allowed within the one hundred (100) year flood plain, the following conditions shall be met:
1. Residential Structures. Within the Flood Plain Conservation District area, the lowest floor, including the basement of any new or improved residential structure, shall be at least one and one half (1 1/2) feet above the one hundred (100) year flood elevation. The structure shall be anchored to prevent collapse, flotation and lateral movement.
2. Nonresidential Structures. Within the Flood Plain Conservation District, the lowest floor, including any basement or storage area, shall be at least one and one-half (1 1/2) feet above the one hundred (100) year flood elevation, or be designed and constructed so that the space enclosed by such structure shall remain completely dry during any flood up to said height. In addition, the structure shall be anchored to prevent flotation, collapse and lateral movement.
A. Zoning Permit shall be required f or all construction and development which includes, but is not limited to, paving, filling, grading, excavation, mining, dredging or drilling operations and the like.
An Applicant wishing to challenge the boundaries of the Flood Plain Conservation District as established by the Solebury Township Zoning Ordinance shall be required to submit the following information to the Township. A report from a soil scientist challenging the soil type found on the soils map is not sufficient to revise the flood plain boundaries in those areas where the flood plain is established by alluvial soils, i.e., those areas not mapped by the detailed flood insurance study.
That information will be reviewed by the Township Engineer who will make a report to the Township. pursuant to Section 1409 of the Zoning Ordinance; all costs, charges and expenses of the review shall be paid by the Applicant.
After review of the information supplied by the Applicant and the Township Engineer's report, the delineation of the Flood Plain Conservation District may be revised. However, pursuant to Section 1406 of the Zoning Ordinance, prior to any such change, approval must be obtained from the Federal Insurance Administration (FIA) or the Federal Emergency Management Agency (FEMA).
Each application must be accompanied by the following information, maps, plans, specifications, design analyses, test reports and such other data and additional information as may be required by the Township:
A. A plan showing the present Flood Plain Conservation District boundaries for the tract in question, determined in accordance with Section 1404 of the Zoning Ordinance. For those tracts where a detailed flood insurance study has been completed by the Federal Insurance Administration, the plan shall show the existing flood plain elevations set forth in the study.
B. Where no detailed flood insurance study has been completed, the plan shall show the alluvial soils as mapped by the Soil Survey of Bucks and Philadelphia Counties, Pennsylvania prepared by the Soil Conservation Service. Alluvial soils include, but are not limited to, Alton Graveley Loam, flooded; Bowmansville Silt Loam; Hatboro Silt Loam; Marsh Loam; Pope Loam and Rowland Silt Loam.
C. A plan showing the location, size and height of all present or proposed buildings, structures or other flood plain obstructions and detailing the topographic features and elevations so as to enable an appraisal of the hazard potential of all obstructions in the flood plain. The plan shall show ground surface elevations at a contour interval not to exceed two (2) feet or shall include cross sections within the area at a maximum of one hundred (100) foot horizontal intervals.
D. A hydrologic and hydraulic report that shall include:
1. For sites mapped by the detailed flood insurance study, all hydrologic data from the detailed study applicable to the tract.
2. For sites where no detailed flood insurance study has been completed, the following information:
a. For drainage areas of three (3) square miles (2,000 acres) or less, use the soil cover complex method (T.R.55) "Urban Hydrology for Small Watersheds" to compute peak discharge.
b. For drainage areas greater than three (3) square miles, use either:
1) PSU-IV procedure developed by Pennsylvania State University for "Estimating Design Flood Peaks on Ungaged Pennsylvania Watersheds"; or
2) The PennDOT method for estimating peak rates of runoff for drainage areas between one and one-half (1-1/2) square miles and one hundred fifty (150) square miles (refer to Section 10.12 PennDOT design manual #2).
E. Calculations completed during the HEC-2 water surface profile programs to compute the one hundred (100) year flood elevation.
F.A plan showing the proposed Flood Plain Conservation District boundaries based on peak surface discharge and water surface profile calculations from paragraphs D. and E. above.
A. BACKGROUND
The following procedures have been established by the Township to facilitate review of a request fora Special Exception, Variance or Conditional Use by the Zoning Hearing Board or the Board of Supervisors, as the case may be. They are designed to provide all of the information necessary to determine whether the application is in compliance with the Township's flood plain regulations.
Prior to the Zoning Hearing Board rendering a final decision on a request for a Special Exception or Variance, or the Board of Supervisors rendering a decision on a request for a Conditional Use, for a proposed use in the Flood Plain Conservation District, the Township Engineer shall review the application and prepare a written evaluation of the information for the Zoning Hearing Board or the Board of Supervisors, as the case may be, advising the Zoning Hearing Board or the Board of Supervisors whether the submission complies with the Township's flood plain regulations. All costs, charges and expenses incurred by the Township Engineer in the review of the submission shall be paid by the Applicant pursuant to Section 1409 of the Zoning Ordinance.
These regulations are in addition to the requirements of the Flood Plain Conservation District contained in the Solebury Township Zoning Ordinance.
B. PROCEDURE
Each Applicant to the Zoning Hearing Board or Board of Supervisors shall submit the following information, maps, plans, specifications, design analysis, reports and such other data and additional information as may be required by the Township, together with the Zoning Hearing Board or Board of Supervisors' application. A Zoning Hearing Board or Board of Supervisors' application that does not contain the information set forth below, shall not be considered complete and shall not be accepted for filing.
1.A plan showing the location, size and height of all present or proposed buildings, structures or other flood plain obstructions and detailing the topographic features and elevations so as to enable appraisal of the hazard potential of all obstructions in the flood plain. The plan shall show ground surface elevations at a contour interval not to exceed two (2) feet or shall include cross sections within the area at a maximum of one hundred (100) feet horizontal intervals.
The plan shall show the present Flood Plain Conservation District boundaries for the tract in question determined in accordance with Section 1404 of the Zoning Ordinance as follows:
a. For those tracts where a detailed flood study has been completed by the Federal Insurance Administration, the plan shall show the existing flood plain elevations set forth in the study.
b. For those tracts where no detailed flood insurance study has been completed, the plan shall show the alluvial soils as mapped by the Soil Survey of Bucks and Philadelphia Counties, Pennsylvania prepared by the Soil Conservation Service. Alluvial soils include, but are not limited to, Alton Graveley Loam, flooded; Bowmansville Silt Loam; Hatboro Silt Loam; Marsh Loam; Pope Loam and Rowland Silt Loam,
2.A hydrologic and hydraulic report that shall include:
a. For sites mapped by the detailed flood insurance study, all hydrologic data from the detailed study applicable to the tract.
b. For sites where no detailed flood insurance study has been completed, the following information:
1) For drainage areas of three (3) square miles (2,000 acres) or less, use the soil cover complex 'method (T.R.55) "Urban Hydrology for Small Watersheds" to compute peak discharge.
2) For drainage areas greater than three (3) square miles, use either:
a) PSU-IV procedure prepared by Pennsylvania State University for "Estimating Design Flood Peaks on Ungaged Pennsylvania Watersheds"; or
b) The PennDOT method for estimating peak rates of runoff for drainage areas between one and one-half (1-1/2) square miles and one hundred fifty (150) square miles (refer to Section 10.12 PennDOT design manual J2).
3) Calculations computing the twenty-five (25) year and one hundred (100) year flood elevations using the latest update of the HEC-2 Water Surface Profile prepared by the U. S. Army Corp of Engineers Water Resources Support Center.
4) Calculations demonstrating that for the twenty-five (25) year flood, all structures are sized to permit all floodwaters to pass without overtopping the road.
5) A plan and analysis of the backwater that will be caused by the stream crossing for a one hundred (100) year flood demonstrating that there will be no adverse impact on any surrounding landowners as set forth in Section 1409 of the Zoning Ordinance. In areas where a detailed flood insurance study has been completed, no rise in the one hundred (100) year flood elevation will be permitted. In areas where no detailed flood insurance study has been completed, a rise of one (1) foot above the natural flood elevation will be allowed, provided that the rise is contained within the property limits of the Applicant. No backwater shall be allowed to flood an adjoining property unless written permission is received from the adjoining landowner or the extent of the backwater is approved by the Zoning Hearing Board.
6) In those situations where an Applicant is also requesting a stream encroachment permit from the Pennsylvania Department of Environmental Protection, Bureau of Dams, Waterways and Wetlands, the Township will not notify the Department of Environmental Protection, Bureau of Dams, Waterways and Wetlands that the project complies with the Township's flood plain and storm water management program until the Zoning Hearing Board has issued a Special Exception or Variance for the project, or the Board of Supervisors has issued a Conditional Use for the projects
7) Once a Special Exception, Variance or Conditional Use has been issued, no construction shall be permitted until the Department of Environmental Protection, Bureau of Dams, Waterways and Wetlands has issued any required permits, and the Township has issued a building permit.
