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<br />e) Willow Springs Creek - the tributary of Willow Springs Creek that is channelized <br />and extends to Wonder World Drive, under IH-35. <br /> <br />1.6.2 Complete field surveys on the City's High Accuracy Reference Network ("HARN") <br />Texas State Plane South Central Zone coordinate system (US foot), NAD 83 horizontal and <br />NA VD88 vertical datum, to be on the same basis as the Federal Insurance Study ("FIS"). The <br />Engineer will provide the required survey data and establish temporary benchmarks in low lying <br />subdivisions to assist with elevation certificate preparation. <br /> <br />1.6.3 Prepare for and attend Advisory Committee meeting number 3. <br /> <br />1.7 TASK 6 - HYDROLOGIC MODEL DEVELOPMENT <br /> <br />The Engineer will: <br /> <br />1.7.1 Utilizing existing hydrologic model data, develop an updated hydrologic model each of <br />the watersheds using Geo-HMS on an ArcView 3.2 platform to develop a georeferenced HEC- <br />HMS model. The Engineer will ensure that the model includes both existing and future land use <br />conditions, utilizing existing City and County GIS data, and will employ the Soil Survey <br />Geographic Database ("SSURGO") soil information to generate runoff curve numbers using the <br />SCS method. <br /> <br />1.7.2 Develop a detailed stream network routing, based on recent 2' LIDAR topography and <br />detention pond rating curve information from City records. The Engineer will compute the times <br />of concentration and the corresponding lag times using the TR-55 method. <br /> <br />1.7.3 Devote particular attention to rainfall intensity and storm frequency in coordination with <br />GBRA, the United States Geological Survey ("USGS") and the National Weather Service to <br />provide additional insight into developing the most appropriate and accurate frequency scenarios. <br />The Engineer will perform a frequency analysis based on the historical record of discharge for <br />appropriate gauges on the Blanco and compare these frequencies to the recently developed <br />USGS regression equations and the current FIS flowrates. <br /> <br />1.7.4 Utilize the frequency analysis to formulate the Early Warning System identified in <br />Section 1.15. <br /> <br />1.7.5 Prepare for an... attend Advisory Committee meetings numbers 3 and 4. <br /> <br />1.8 TASK 7 - HYDRAULIC MODEL DEVELOPMENT <br /> <br />The Engineer will: <br /> <br />1.8.1 Update the existing conditions hydraulic models using existing model data from FEMA, <br />the collected field survey data, information from design plans and recent LIDAR topographic <br /> <br />Espey Agreement <br /> <br />4 <br />