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<br />. <br /> <br />. <br /> <br />- /' <br /> <br />(1) Observations shall be made of the character of <br />the drainage basins as it will affect drainage runoff and of the <br />streams and flood plains as it will affect their capability to <br />convey floodflows. Results of these observations shall be uti- <br />lized along with good engineering judgment to develop reasonable <br />hydrologic criteria, including, but not limited to, flood routing <br />criteria, Mannin's "n" values, and reasonable infiltration losses. <br /> <br />(2) Photos shall be taken at selected locations of <br />probable future flooding within the delineated flood plain reach <br />for reproduction in the report, similar to samples furnished. <br />Each site photograph of probable future flooding shall show a <br />stadia rod which can be clearly read. The stadia rod pattern shall <br />be similar to, or equal to, Keuffel & Esser Co. flexible stadia <br />rod, pennant pattern, 3-1/2xI4 " , K&E 811089. <br /> <br />(3) Photos shall be taken of typical reaches of the <br />stream and flood plain for verification of "n". values used for <br />hydraulic computations. <br /> <br />(4) Investigatic,lns shall be made of existing and <br />potential developments that do or might encroach on the flood <br />plains within the next two to five years, with particular concern <br />for features that would obstruct floodflows in the reach to be <br />delineated. Any developments (channel modifications, bridges, <br />etc.) for which plans are filed with the city or county at the <br />date of signing this contract shall be incorporated in the report. <br /> <br />:i. <br /> <br />b. Field Surveys. - Field surveys shall be accomplished 'as <br />necessary for verification of the map provided under paragraph 5 <br />above, for determining stadia board photo elevations, and for <br />making backwater computations and profiles discussed hereinafter. <br />Vertical control for the report shall originate from third order <br />survey based upon bench marks set by the united States Geological <br />Surveyor furnished by the contracting authority. All cross <br />sections and bridge sections shall be performed to an accuracy with <br />an allowable horizontal error of closure of one part in 200. All <br />cross sections, elevations, bridge sections, and vertical circuits <br />shall be performed within an allowable vertical error of closure <br />of 0.1 ft/miles. Original notes, field books, computations, <br />sketches, and other basic data developed by the engineer under this <br />contract shall be available for review by the contracting authority. <br /> <br />, <br />!. <br />, <br /> <br />" <br />, <br /> <br />i <br />~ <br />" <br /> <br />c. Hvdroloqic Analysis. - Hydrologic analysis used as a <br />basis for development of peak discharge for 'the 10 and 25 year <br />floods, the IRF, and the SPF shall be performed as follows: <br /> <br />i <br /> <br />-2- <br />