Erosion Assessment for 16 Urban Watersheds - Austin, Texas

Developed a watershed erosion assessment report for each of the 16 urban watersheds. The studied watersheds are East Bouldin, West Bouldin, Blunn, Fort Branch, Tannehill Branch, Boggy, Shoal, Johnson, Waller, Barton, Walnut, Buttermilk, Bull, Harper’s Branch, Little Walnut and Country Club Creek. Obtained and reviewed previous studies and reports from City, State and Federal entities. Developed stream inventory for approximately 170 miles of stream length. Performed field reconnaissance, obtained field samples, took over 900 photographs, and surveyed typical stream sections. Defined and prioritized erosion problems. Performed geomorphic survey including identification of inset, bankfull, and top of bank flows from stream indicators, development of curves to show channel response over time, and development of channel enlargement ratios. Evaluated enlargement potential and sediment transport. Developed erosion hazard indicators for each watershed. Prepared channel erosion management recommendations.

Tannehill Branch, Erosion Control Projects at Givens Park and Bartholomew Park - Austin, Texas

Bartholomew Park. Coordinated with subconsultant to prepare “natural channel” design which incorporates floodplain creation and bioengineering to maintain bed load transport and flow conveyance in a stable channel system. A HEC-RAS model was prepared to determine depth, velocity, and shear stress for the bankfull and flood storm events. Prepared construction documents including grading control structures, stream bank restoration plan and cross-sections, drop structure and stilling basin and construction specifications. Provided construction phase services.

Givens Park. Performed field reconnaissance, prepared preliminary design and final design to stabilize the stream banks and maintain bed load transport. Different techniques such as geogrid, large boulders, erosion fabrics, and bioengineering were employed to manage the channel erosion while creating a natural channel appearance. Prepared construction plans including erosion / sedimentation control plan, stream bank stabilization plan and cross-sections, construction details and dewatering plan, prepared project manuals, and provided bid support. Provided construction phase services to insure general conformance with the construction documents.

Shoal Creek Greenbelt Hike and  Bike Trail Repairs - Austin, Texas

The Shoal Creek Hike and bike trail experienced erosion problems in the lower reaches of Shoal Creek, often completely washing the trail out at some locations along the top of the channel banks. The project designed solutions for nine separate erosion locations along Shoal Creek in the area from 6th Street to 29th street.

Use of natural materials was incorporated wherever possible. 

Performed field reconnaissance to rank erosion problems along the creek in order of severity. From this list, nine areas were selected for improvements. Preliminary and final designs were developed using varying techniques such as limestone boulders with geogrid for stability, erosion matting, permeable concrete for trails, and bioengineering were employed to manage erosion of the trails while creating a natural appearance for the channel. Prepared construction drawings including erosion / sedimentation control plans, stream bank stabilization plans, trail traffic control plans, construction details and dewatering plans, prepared project manuals, and provided bid support. Provided inspection and construction phase services, and assisted with change orders and contractor pay applications.

La Frontera Center, Water Quality & Wet Pond - Round Rock, Texas

The La Frontera Section I and II development in Round Rock, Texas is a 113 acre commercial retail center. The development is located at the northwest corner of IH-35 and FM 1325 in Round Rock, Texas. In addition to complying with the City of Round Rock’s development regulations, a portion of the property lies within the northern Edwards’ Aquifer recharge zone and as such complied with the Texas Commission of Environmental Quality’s (TCEQ, previously the Texas Natural Resources Conservation Commission) Edwards’ Rules (amended 1999). Raymond Chan & Associates, Inc. was in charge of planning and designing a regional stormwater detention facility to protect downstream properties (structures within the floodplain), and to design a stormwater quality treatment facility to help protect the northern Edwards’ Aquifer. In addition, three downstream road crossings (Old West Drive, Purple Sage, and Yucca Drive) were sub-standard and did not allow for safe passage in a 25-year storm event. RC&A performed a hydrologic analysis on this tributary of Lake Creek and designed culvert improvements for the three road crossings.

Town Lake Park Wet Pond - Austin, Texas

The Town Lake Park water quality wet pond will be located in the northwest quadrant of the Palmer Events Center in accordance with the approved master plan.  The pond will collect, treat, and detain stormwater runoff from approximately 18.3 acres of the site, which includes the following areas:

-          Palmer Community Events Center building (rooftop runoff),

-          the parking garage,

-          the proposed parking and drive area near the Dougherty Arts Center,

-          the children’s outdoor arts center,

-          the open meadow inside the large oval sidewalk,

-          and the area in the immediate vicinity of the pond.

West Bouldin Creek, Watershed and Stream Corridor Restoration Plan - Austin, Texas

West Bouldin Creek, an urban watershed with a drainage area of 2.9 square miles, is essentially developed without stormwater management controls since urbanization occurred prior to the requirement of stormwater detention and water quality controls. The City desires to complete a study that identifies restoration opportunities and develops a plan for future improvements to restore the West Bouldin Creek stream corridor. The project has two primary purposes. One is to assess the potential to improve watershed and stream corridor conditions in West Bouldin Creek to achieve water quality treatment and erosion control in a synergistic manner. The second purpose is to provide preliminary design drawings of a limited number of water quality retrofit sites that incorporate stream restoration and streambank erosion management features to the extent possible.

Erosion Assessment for Onion Creek Watershed - Austin, Texas

Raymond Chan & Associates, Inc., in association with Aquafor Beech Limited, and the City of Austin Watershed Protection and Development Review Department undertook a study to assess the erosion related characteristics of Onion Creek from the Hays/Travis County Line to the Creek’s confluence with the Colorado River.  The total stream study length was approximately 27.9 stream miles.  Onion Creek, at the confluence with the Colorado River, has a contributing watershed area of almost 350 square miles. 

The Tasks encompassed in the Study included: Stream Inventory, Geomorphic Analysis,  Particle Grain Size Analysis, Erosion Classification, The Adjustment Process, Channel Enlargement, Sediment Transport,  Rapid Geomorphic Assessment,  Hydrologic and Erosion Model, and Stream Corridor Management Plan.