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In riverine systems, bridges typically represent an obstruction to channel and floodplain flow. The obstruction to flow can be a source of substantial energy loss. In order to appropriately model the energy loss due to a bridge in HEC-RAS, there are some things you should know.

Bridge modeling in HEC-RAS has several components:

  • Bounding cross sections
  • Ineffective flow areas
  • Bridge opening

This post provides the information necessary to model a simple bridge using HEC-RAS.

Bounding Cross Sections


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The Texas Water Development Board (TWDB) is holding a period of public review and comment before approval and adoption of the draft State Fiscal Year (SFY) 2014 State Revolving Fund (SRF) Intended Use Plans (IUPs) expected on August 15, 2013. These documents are available online:

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TagsTWDB, Funding,

The FEMA Risk Map Outreach Team recently released the following statement regarding new capabilities to their Online Letter of Map Change:

We are pleased to announce that FEMA has successfully launched new capabilities to the Online Letter of Map Change (LOMC)! Requestors may now submit both Amendment and Revision applications through Online LOMC. This convenient web tool is now an alternative to the paper MT-EZ, MT-1, and MT-2 forms.

There are many benefits to applying for a LOMC online:

  • Submit, pay, and upload supporting documentation for
  • ...

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For a limited time, the Texas Water Development Board (TWDB) has some remaining loan and principal forgiveness (grant) funds available from both the State Fiscal Year(SFY) 2013 Drinking Water State Revolving Fund and Clean Water State Revolving Fund programs.

Freese and Nichols can assist you in preparing the Project Information Forms required to obtain these loans.The last day to submit a Project Information Form is June 25, 2013. Please contact Jill Trevino with questions about these funding ...

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The Texas Commission on Environmental Quality recently opened its Section 319(h) Nonpoint Source Grant Program. Eligible applicants include Texas agencies, political subdivisions of the State of Texas, and nonprofit organizations. The grant provides a 60-percent federal match to develop or implement Total Maximum Daily Load studies (TMDLs) and Watershed Protection Plans (WPPs). Applications are due July 31, 2013 at 3:00 P.M. Additional program details are found at

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Congratulations to four Stormwater Engineers for recently receiving precertifications from the Texas Department of Transportation.

Top Row

Luis Alday, San Antonio, was approved in two categories:

  • 10.1.1, Hydrologic Studies
  • 10.3.1, Complex Hydraulic Design

Scott Berman, Fort Worth, was approved in two categories:

  • 10.2.1, Basic Hydraulic Design
  • 10.3.1, Complex Hydraulic Design

Lower Row...

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This year’s Texas Floodplain Management Association (TFMA) Spring Conference was held in Sugarland, Texas from May 21-24, 2013.

Freese and Nichols’ staff presented with the City of Round Rock on the partial decommission of Stone Oak Dam, which is now available for download (click the title to view the presentation):

Stone Oak Dam: To Breach or Not to Breach, That is the Question

  • Kim Patak, P.E., CFM, CPESC – Freese
  • ...

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Congratulations to six Freese and Nichols employees, who are now Certified Floodplain Managers (CFMs). Last week, the individuals attended the Texas Floodplain Management Association conference in Sugarland, Texas, where they participated in the Floodplain Management 101 one-day course, led by the Texas Water Development Board. During the course, they all completed and passed the CFM exam.

From the Dallas office (top row):

  • Katie Hogan, P.E.
  • Trey Shanks

From the Fort Worth office (top row, right):

  • Justin Naylor, EIT

From the...

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