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<br />San Marcos Floodplain Management Plan: A Sustainable Future for Floodplain Management <br />Application for Flood Protection Study Grant <br /> <br />11) Benefit / Cost Analysis - The benefit of each alternative in terms of level of <br />protection/reduction of flood damages~ impacts, right-of-way requirements, <br />environmental impacts~ etc. will be made in comparison to the associated cost of <br />each improvement GIS methods will be employed to facilitate and fine-tune the <br />combination of solutions. The City has already developed numerous GIS datasets <br />for parce1s~ structures~ and infrastructure~ and has recently acquired aerial <br />orthophotography and topographic data. Overlaying existing and proposed <br />floodplains to these base layers will not only provide an efficient means of <br />tabulating potential damages~ but also enable great flexibility in modeling "what- <br />ir scenarios to refine the proposed solutions or offer other possible combinations <br />of solutions. The ease of creating "smart" models of inundation depth (ArcGIS) <br />and velocity profiles (HEC-GeoRAS) will also assist in damage estimation and <br />refinement of proposed solutions. From this benefit/cost analysis, a set of <br />optimum solutions will be presented in a report, which will document the benefit <br />cri.teri~ cost information and other considerations. The purpose of this report will <br />be to communicate the results of the Project to a broad audience that may include <br />technical and non-technical people. The results of the Benefit-Cost Analysis will <br />be presented at a public meeting. <br /> <br />12) Preoaration of Elevation Certificates - For properties located in Special Flood <br />Hazard Areas, slab elevations will be surveyed. A$ appropriate based on need, <br />the City will prepare FEMA Elevation Certificates for property owners. <br /> <br />13) Implementation and Phasing - Following the public input pertaining to <br />Benefit/Cost for the flood protection scenarios, the project will also include <br />recommendations for the implementation and phasing of the identified <br />improvements, both structural and non-structural. The implementation plan will <br />identify potential. funding sources for the improvements, such as city drainage <br />utility fees, impact fees, public/private partnerships~ special utility districts, etc., <br />as appropriate. Consideration of the City's current Capital Improvements Plan <br />and the City's Comprehensive Plan will be important to ensure that the <br />recommended flood protection strategies are coordinated and consistent with the <br />broad objectives of the City. <br /> <br />14)Additional Topics - There are additional topics which will be evaluated during <br />the course of the work structure, in large part with input from the participating <br />entities. First, as a possible non-structural solution, the potential of developing a <br />more formalized Early Flood Warning System will be explored. Currently, the <br />City relies on internet readings of rainfall amounts and only one gauge on the <br />Blanco near Kyle. Further~ this streamflow gauge is often unreliable. To <br />correlate this rainfall and streamflow information to flood level, the City relies on <br />manual flood stage readings from bridges, and based on the sum of this <br />information, makes a decision to evacuate low-lying areas or not. <br /> <br />Developing a framework to improve the quality of information available to the <br />City during a flood event will involve close coordination with GBRA and <br /> <br />M:lactive104P012 San Marcos M.D.P1Gront Applic-SMa.doc J 6 <br />Exhibit A, Page 20 <br /> <br />December 16. 2004 <br />