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Purgatory Creek Watershed Storm Drain Study <br />EXHIBIT 1 -SCOPE OF SERVICES <br />Scope of services includes professional engineering services associated with the 1D/2D storm drainage <br />analysis of the Purgatory Creek watershed within San Marcos, Texas. The study area includes <br />approximately 2 square miles as shown in Exhibit 1.1 . Phase I includes the Infoworks-ICM initial model <br />setup, calibration, inundation mapping and identitication of problem areas and Phase II will include <br />additional analysis based on the results of this study and development of solutions to the problem areas <br />identified. The following sections include a description of the scope of services, the work breakdown <br />structure, budget and schedule. <br />This scope of this study includes the level of effort necessary for the initial set up the Infoworks-ICM model <br />for the study area and conduct an assessment of flood conditions. While multiple storm events will be <br />executed to ensure that the model is robust, the primary intent is to identify areas that do not currently <br />meet the City's 25 -year design storm criteria. The results of this study will inform needs to be addressed in <br />the Phase II scope which may include adjustments or refinements to the model to provide more detail <br />and/or correct topographic issues (i. e. addition of break lines, etc.), identify specific problem areas in need <br />of improvement, etc. <br />WORK BREAKDOWN <br />The following tasks have been identified to complete this scope of services. <br />Project Initiation — Upon notice to proceed, LAN will initiate the project to include a kick off <br />meeting with the City of San Marcos. Initiation includes the following: <br />a. Review study limits (see Exhibit 1.1 .) and level of detail in a kick-off meeting with the <br />City of San Marcos including review and agreement of initial survey effort. <br />b. Data collection (LiDAR, storm drain layouts, GIS layers, HEC-RAS/HMS, etc.). <br />c. Collect field survey of storm drains (pipe inverts and inlets) and culverts (invert elevations, <br />dimensions, pipe material, etc.). See proposal by McGray & McGray ( Exhibit 1.2 ). <br />d. Integration of field survey in City GIS including site visit(s). <br />2. Existing Conditions Infoworks ICM Model - This task includes the assembly of geometric data, <br />development of hydrologic data and development of a functioning Infoworks model as described in <br />the following: <br />2.1 Geometric Data <br />a. GIS data preparation for importing into Infoworks (storm drain data, building footprints, <br />land use, LIDAR format conversion, etc.). <br />b. Infoworks model construction: <br />L Create ground surface (import LIDAR) <br />ii. Import GIS data (land use/roughness zones, storm drain, culverts, etc.) <br />iii. Mesh creation <br />c. Model adjustments, corrections and verification. <br />2.2 Hydrologic Data for Rain on Mesh Simulations <br />a. Develop rainfall input from USGS rainfall report consistent with InFRM report dated <br />September 2016, apply loss rate and apply SCS Type III distribution to obtain rainfall <br />