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Home My WebLink AboutDrainage StudyDrainage Study CREEK MEADOWS SUBDIVISION Section 1A (Phase 1 & 2) & Section 1B College Station, E.T.J. Brazos County, Texas .. � , '111 • "(P o .... OF h • RABON A. METC ELF ......• 83 . FOR March 8, 2007 RME No. 202 -0286 Prepared For: Creek Meadow Partners, L.P. 230 Southwest Parkway East College Station, TX 77840 Prepared By: Rabon Metcalf Engineering P.O. Box 9253 College Station, TX 77845 Creek Meadows — Section 1A & 1B Drainage Study Rabon Metcalf Engineering March 8, 2007 into a well - defined creek that develops along the southern property line of the subject tract. This unnamed tributary is well defined and natural in nature downstream of these existing stock ponds. Runoff then drains southwesterly, under Greens Prairie Trail and ultimately into Peach Creek, thence to the Navasota River, thence to the Brazos River and ultimately to the Gulf of Mexico. It should be noted that the existing 9' CMP, that conveys runoff under Greens Prairie Trail, has historical evidence that it is undersized and that Royder Road upstream and downstream of this drainage structure frequently is inundated with floodwater and backwater from the drainage structure. The tract is unimproved with land -cover general consists of open grassy areas with some thick brush, weeds, and trees along the unnamed tributary. Elevations range on the site from approximately 287' Mean Sea Level (MSL) to approximately 342' MSL. The Brazos County soil maps indicate that this area is comprised of Type C and D soils which consist of clays or silty clay /sand mixtures. 1.4 FEMA Information: The entire master planned Creek Meadow subdivision does not lie within mapped 100 - year floodplain as graphically depicted by the Federal Emergency Management Agency (FEMA) — Flood Insurance Rate Map (FIRM) Community/Panel number 480083 0201D, with an effective date of February 9, 2000 and Panel number 48041C 0200C with an effective date of July 2, 1992. A portion of this FIRM Panel Maps is located in the "Attachment" section of the Drainage Report. 2.0 WATERSHEDS & DRAINAGE AREAS 2.1 Unnamed Tributary Watershed: As previously discussed, the Creek Meadow subdivision is located in a watershed of an unnamed tributary that drains into the Peach Creek Drainage Basin. Since the drainage study will include the hydrologic /hydraulic modeling of both detention facilities and floodplain evaluation of the unnamed tributary two drainage basins were considered and analyzed and are described as follows. The Existing Conditions Drainage Area Map is located in the "Attachment" section of the Drainage Report. Drainage Area "X1" — This drainage area is approximately 272 acres and will consists of the areas of Creek Meadows subdivision, Section 1A, 1B, portions of 2, 3 and 4 at pre- development or existing conditions. Portions of Section 2 that lie outside of this drainage area will have stand -alone detention facilities that will be analyzed and constructed with those subsequent phases of development. Sections 5, 6, and 7 of Creek Meadows, which lie south of these drainage area and Greens Prairie Trail will also have stand -alone detention facilities that will be analyzed and constructed with those subsequent phases of development. 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