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I . I I I I I I . I I I I I I I I ,. . 23 Flood waters which originate within the Central Basin are conveyed to the box cul vert at Ci ty Park vi a the street system. Many of the streets in the Central Basin are not curb and guttered, and have only minimal asphaltic sur- faces. Additionally, the lack of curb and gutter in combination with residences with first floors which are lower or at grade with adjacent street crowns create the potenti a 1 for basement and fi rst floor fl oodi ng of res i den- ces. This is particularly apparent along Arkansas and Otero Avenues, and along Railroad Avenue and Second Street. Ponding of stonnwater along the rail road grade promotes insect i nfestati on, and mai ntenance probl ems for the adjacent streets and intersections. Western Flow Path: Flooding within this area of Ordway would result from runoff which origi nates immedi ately north of the Town, and from flows out of the Northwest Basin. County Road 17 has provided the conveyance of these flows in the past. Once the capacity of County Road 17 is exceeded, the flood waters would spread over the agricultural areas west of County Road 17, and to the Ordway West area of Town. No structures are impacted, other than publ ic facilities such as road intersections and culverts. Debris deposition within agricultural areas would be the primary type of damages which could occur from shallow floodwaters moving overland. As a result of the hydraulic analysis of the existing drainage system, structures which could be impacted by a 100-year flood was tabulated. Table 8 1 ists the structures which would probably be impacted by shallow flooding associated with a 100-year flood event. All of these structures lie within areas where 1- to 2-foot flooding depths are possible due to inadequate storm drainage facilities or inadequate curb and gutter systems which cannot prevent the spreadi ng of flood wa ters pass i ng through streets. The tabul ati on was used in the estimation of flood damages. Basi s of Design The hydraul; c analysi s of the ex; sti ng systems and eventual alternati ves combined the HEC-2 analysis with normal-depth calculations for proposed storm sewer systems. The analysis enabled the planning of improved channel sec- tions, stonn sewers, and crossings for later cost estimation.