May 16, 2017

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Geosyntec Presentations at the ASCE-EWRI World Environmental & Water Resources Congress

Scott Struck (Colorado), Turgay Dabak (Washington, D.C.), Aaron Poresky, and Lucas Nguyen (Oregon), will present papers at the American Society of Civil Engineers (ASCE) - Environmental & Water Resources Institute (EWRI) World Environmental & Water Resources Congress in Sacramento, California on May 21-25, 2017.

The theme of the conference is "Creative Solutions for a Changing Environment." The ASCE represents more than 150,000 members of the civil engineering profession in 177 countries. Founded in 1852, ASCE is the nation's oldest engineering society. Created in 1999, the EWRI is the recognized leader within ASCE for the integration of technical expertise and public policy in the planning, design, construction, and operation of environmentally sound and sustainable infrastructure impacting air, land and water resources.


Scott Struck
Title: 244697 - Playing in the Park: Omaha's Implementation of Larger Scale Green Infrastructure in Parks to Control Combined Sewer Overflows
Date: Thursday, May 25
Time: 2:18 – 2:36 p.m.

The City of Omaha Public Works Department has committed to implement green infrastructure (GI) projects within their Long Term Control Plan. These projects will help to reduce the volume, duration, and magnitude of combined sewage into the receiving streams by controlling the amount of stormwater that is allowed into the combined sewer system (CSS). The primary goal of the pilot program is to help demonstrate the effectiveness of different practices that help reduce stormwater runoff to the CSS. As in many urban watersheds, space is constrained to locate larger GI practices, limiting stormwater management opportunities. Parks are one of the few public parcels that allow for adaptation of park space to accommodate stormwater management. Coordination with many City Departments is critical to the adoption and success of the projects.

Omaha has initiated or completed more than seven projects in public parks. This presentation will highlight several of these. Two of the first projects are Field Club Trail (FCT) and Hanscom Park (HP). These projects serve larger neighborhood areas, including up to 200 acres in the FCT project area and 150 acres in the HP area. This presentation will highlight the planning process, design considerations, public outreach, and challenges that go into efficiently developing large GI practices within public park systems and their impacts on overflows. These projects will also serve as a means for the City to better understand the required operations and maintenance (O&M), and establish a better understanding of the life cycle costs to determine future GI opportunities.

Turgay Dabak
Title: 249176 - Two-dimensional Dam-breach Flood Modeling and Inundation Mapping with Cascading Failures
Date: Tuesday, May 23
Time: 4:44 – 5:06 p.m.
Co-Authors: Marcus Altinakar, University, MS 38677 – The University of Mississippi; Wilbert Thomas, Alexandria, VA 22304 – Michael Baker International; Chad Scroggins, Pelham, AL 35124 – Shelby County; Trey Gauntt, Pelham, AL 35124 – Shelby County, Alabama; Hubbard Harvey, Columbiana, Alabama 35051 – Shelby County, Alabama

Shelby County is the fastest growing county in Alabama. The county encompasses approximately 808 square miles in central Alabama and has 11 high-risk dams. The present paper presents a dam-break study in support of the Shelby County Department of Development Services for developing emergency action plans and for other planning purposes. The study involved two-dimensional numerical modeling of four dams located in the Oak Mountain State Park, which are within the Cahaba Valley Creek basin (a.k.a. Bishop Creek): Double Oak Lake, Lake Tranquility, Beaver Lake, and Lunker Lake. The modeling and simulations were carried out using the DSS-WISE™ software and included the sunny day breach and probable maximum flood (PMF) breach scenarios. A PMF base scenario with no dam breaches was also simulated. The simulations included individual breaching of each dam as well as the cascading failure of the Lunker Lake Dam and Beaver Lake Dam. Modeled PMF conditions were based on the inflow design flows generated by the 90% of the probable maximum precipitation (PMP) distributed over the upstream drainage basins of the dams. The hydrologic simulations were carried out using an existing USACE HEC-HMS modeled developed for a hydrologic study performed as part of FEMA's flood insurance study. The paper presents the results of the hydrologic study and the two-dimensional modeling of cascading and individual dam-breach flood modeling and inundation mapping. It also briefly discusses how the results were used by the county for the development of emergency action plans and for other purposes.

Aaron Poresky & Lucas Nguyen
Title: 248978 - Case Studies of Continuously Monitored Adaptive Control (CMAC) of Stormwater Facilities for Stream Protection and Ecological Flow Management
Date: Thursday, May 25
Time: 9:42 – 10:00 a.m.
Co-Authors: Jamie Lefkowitz, Boston, MA – OptiRTC; Lucas Nguyen, Portland, OR – Geosyntec Consultants; Owen Cadwalader, San Francisco, CA – OptiRTC

A Continuously Monitored Adaptive Control (CMAC) approach for stormwater facilities can improve performance for stream protection and ecological flow management while allowing operations to be adapted over time. Pilot projects across the US over the last 5 years have demonstrated the benefits of applying CMAC to stormwater facilities. Moving from pilot applications to broader adoption for watershed protection requires (1) tools to estimate long-term performance, and (2) monitoring and validation of estimates based on real-world operations.

This presentation will highlight three case studies where improvements in stream protection and ecological flow management have been modeled and/or validated:

1) Development and application of a CMAC analysis tool that interfaces with the Western Washington Hydrology Model. The WWHM model is now available nationwide and provides potential for broad geographic utility. This case study also included trial applications of the tool to a real project.
2) Modeled CMAC performance for stream protection and ecological flow management in different climate zones around the country, including assessment of the effect of forecast uncertainty.
3) Monitored CMAC performance for a regional detention pond in Oregon from fall of 2015 to present. Monitoring data have been evaluated for a wide range of stream stability and ecological metrics. Monitored CMAC performance was also compared with model results.

The emphasis of this presentation will be to introduce key studies and tools that are available to help municipalities, researchers, and consultants evaluate the potential role for CMAC in watershed protection efforts.

More Information

For more information regarding the event, visit:
For more information on changing environment solutions, contact Scott Struck at This email address is being protected from spambots. You need JavaScript enabled to view it. or Turgay Dabak at This email address is being protected from spambots. You need JavaScript enabled to view it. or Aaron Poresky at This email address is being protected from spambots. You need JavaScript enabled to view it. or Lucas Nguyen at This email address is being protected from spambots. You need JavaScript enabled to view it..
To learn more about Scott see his profile at:
To learn more about Turgay see his profile at:
To learn more about Aaron see his profile at:
To learn more about Lucas see his profile at: