Stormwater Management and Hydrological Analysis

MoPac-South/State Highway 45 Drainage

This project consisted of the design of MoPac-South from U.S. 290/S.H. 71 to its southern terminus and SH 45 from FM 1826 to its intersection with MoPac­ South. Murfee Engineering Company was responsible for the drainage design and bridge and culvert hydraulic analysis/design. This includes bridge crossings of Williamson, Slaughter, and Danz Creeks for the length of the project. The Danz Creek hydrologic analysis included a stream bifurcation which required a split flow analysis to determine the design flows for the proposed crossings. The design has been in phases beginning in 1986 and continued through 1989. The TR-20, HEC-2, and THYSYS computer programs were used to support the design.

Springbrook Centre Regional Detention

This project consisted of design of a three stage regional detention pond system for the upper Gilleland Creek watershed beginning at Picadilly Lane and continuing upstream. The first phase of the system consisting of two ponds was constructed by Cash Construction Company for a price of $1,246,921.45. Construction began in October 1987 and was completed the following year. This project was funded as part of an interlocal agreement between the City of Austin and John Lloyd Development. Murfee Engineering was responsible for the preliminary planning, preparation of a regional detention and dam safety analysis, construction plans and the contract administration/inspection for this project. The U.S. Department of Agriculture Soil Conservation Service (USDA SCS) TR-20 computer program was used to determine the storm discharges, the U.S. National Weather Service (U.S. NWS) DAMBRK computer program was used for the dam safety analysis. The U.S. Army Corps of Engineers HEC-2 Water Surface Profiles and the Texas State Department of Highways and Public Transportation (T.S.D.H.P.T.) THYSYS computer programs were used to provide input to the previously referenced programs.

Circle C Regional Detention

This project has consisted of floodplain determinations and detention analyses for the Circle C Ranch development in upper Slaughter Creek, Williamson Creek and Bear Creek watersheds. The hydrologic and hydraulic analysis includes the following creeks and their tributaries: Slaughter Creek from near FM 1826 to its exit from the development near Brodie Lane, Danz Creek from FM 1826 to its confluence with Slaughter Creek, and floodplain determination for an unnamed tributary to Bear Creek. Associated with the development are the downstream wastewater interceptors and the necessity of locating such out of the 100-year floodplain. For the various phases of these interceptors, floodplain determinations were made of Slaughter Creek from the above mentioned locations downstream to IH-35. The results of the above floodplain delineations served as input for the planning and design process for the Circle C Ranch development. Determination of these floodplains and detention analyses began in 1983 and continued through 1990. The TR-20, HEC-2, DAMBRK, and THYSYS as well as the HEC-1 Flood Hydrograph Package computer programs have been used for these analyses.

Little Walnut Creek Watershed Master Plan

This project, for the City of Austin, consisted of the hydrologic and hydraulic analysis of the urban watershed. The scope included the evaluation of the creek with respect to erosion problems and identification of structures in the floodplain.

Little Walnut Creek Erosion Control Projects

Murfee Engineering, in association with RJ Brandes Company completed the design for several erosion control projects along Little Walnut Creek in the City of Austin. Design elements included gabions as well as earth retaining systems designed to provide a supportive medium for vegetation.