Urban Storm Drain Design: Cooperation with Municipalities

Building off of TXDOT ROW• In some cases, intersecting off-system streets

introduce flow of such quantity that desired ponded width is exceeded at the intersection

• Inlets on project roadways and TxDOT ROW cannot prevent undesirable conditions

• Flow must be intercepted upstream (on the off-system street) before it reaches the project roadway

• This may require construction of storm sewer laterals and inlets off of the TxDOT system (typically city streets)

Building off of TXDOT ROW

• Policy and law closely regulate the expenditure of TxDOT-managed funds off-system

• Cost participation by the local public agency (city) to pay for portions of the storm sewer off-system may be required

• This is done through an Advanced Funding Agreement (AFA)

• AFAs must be executed very early in the project development process

• AFAs often take a very long time to execute and can delay a project if not executed early

Building off of TXDOT ROW

• It is essential to determine whether or not an AFA will be needed prior to beginning the PS&E development process

• This implies that such situations are identified before basic processes are begun

• Early project reconnaissance, during a rainfall event if at all possible, photographs, interviews with local officials and adjacent businesses and landowners, and visual evaluation of topography are all techniques that contribute to early identification of the need for an AFA

• Construction off-system and the execution of an AFA may affect the environmental clearance process

Building off of TXDOT ROW

• For assistance with AFA execution, consult GSD-Contract Services Section