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7 The reach from Evans to Iliff consists of a concrete box culvert varying in size from 2-14' x 4.5' barrels at Iliff to 2-15' x 4' barrels at the outlet. The conduit passes between two apartment buildings and beneath parking lots for the apartments, a depart- ment store and a gas station. Figure 7 shows the inlet to the conduit at Iliff Avenue. Figure 8 shows the alignment of the culvert through the department store parking area. Above this reach, flood waters will leave the main channel because of the limited capacity of the Iliff-Evans conduit. As a result, flood waters will pro- ceed across the parking areas and onto and along Monaco Boulevard to Cherry Creek. Many properties, including the apartment buildings, the gas station and other small busin~sses within the reach will be inundated by the lOO-year flood. Houses east of the gulch and south of Iliff will also be flooded. This reach is shown on Drawing G-3. The reach from Iliff to Yale, Drawing G-4, is a grass-lined open channel. This reach has been channelized as a result of the de- velopment in the area. The flood plain is confined to the existing channel, but backwater above Yale will cause some shallow flow in South Newport. From Yale to Hampden Avenue, the flood plain is contained within a well defined area. A significant feature of this reach is the crossing at the Highline Canal. The crossing structure is a 48" pipe for the gulch passing beneath the Highline Canal. The pipe is inadequate and will cause flood waters to overtop and be in- tercepted by the Highline Canal causing possible breaching and localized flooding along the canal. The Yale Avenue crossing is inadequate to pass the 100-year flood without overtopping. Figure 9 shows the Yale Avenue culverts while Figure 10 shows the channel downstream of Yale Avenue. Figure 11 shows the extent of flooding in Bible Park above Yale Avenue during the May, 1973 flood. Figure 12 shows the extent of flooding above the Highline Canal and Dartmouth Avenue during the same flood. The 100-year flood plain through the reach is shown on Drawings G-4 through G-7. Between Hampden and I-225, the gulch passes through an improved residential green belt and a city park. Figure 13 provides a view of the green belt and the crossing structure at Kenyon Avenue. The 100-year flood flow will exceed the capacity of the greenbelt channel and spill onto Tamarac Drive. The residences along Tamarac Drive and Spruce Street are constructed high enough to be out of the 100-year flood plain although Tamarac Drive will be impassable during a 100-year flood event. Figure 14 shows the flooding situation at Tamarac Drive and Princeton during the May, 1973, flood. Through Rosamond Park, little flood damage is anticipated during the 100-year flood except for erosional damage along the gulch and on the path embankments. At Quincy Avenue, approximately 23% of the estimated 100-year flow will pass over the road. The newly constructed crossing should be considered adequate for the 10- year flow and should sustain little, if any, damage during the 100-year storm. The flood plain through the Hampden to I-225 reach is shown on Drawing G-7 and G-lO. The reach from I-225 to Belleview is shown on Drawings G-lO and G-ll. Through this reach, the gulch adjoins developed and de- veloping land on the east and undeveloped areas of the Denver Technological Center on the west. The 100-year flood plain is confined to the channel bottom except for flood plain fringes ex- tending onto Wabash Street, north of Belleview, and flood over- flows on Tamarac Parkway under I-225. The double 12' x 6' box culvert under I-225 is inadequate to carry the 100-year flow, thus flood waters will pond along the south side of the road embankment until it reaches the elevation of the roadway at which point the water will flow along Tamarac Parkway, through the underpass, and, back into the gulch above Quincy.