Sheet 1 of 6

United States

Mexico

TYPICAL CROSS SECTION - BEFORE

FLOODPLAIN LATERAL FLOW ANALYSIS

Lower Rio Grande Valley
By Greg Gentsch, P.E. September 30, 2019

 Sheet 2 of 6

RISING STAGE
FLOODPLAIN

United States

Tributary inflow to floodplain

TYPICAL PLAN VIEW

FLOODWAY

FLOODPLAIN

Mexico

Tributary inflow to floodplain

FLOODPLAIN LATERAL FLOW ANALYSIS

Lower Rio Grande Valley
By Greg Gentsch, P.E. September 30, 2019

 Sheet 3 of 6

RECEDING STAGE
FLOODPLAIN

United States

Tributary inflow to floodplain

TYPICAL PLAN VIEW

FLOODWAY

FLOODPLAIN

Mexico

Tributary inflow to floodplain

FLOODPLAIN LATERAL FLOW ANALYSIS

Lower Rio Grande Valley
By Greg Gentsch, P.E. September 30, 2019

 Sheet 4 of 6

Floodplain

Floodway

United States

A less obstructed and well maintained riverbank will lower the flood elevation
since there will be less obstructing vegetation on the banks in the floodway.

RIVERBANK CROSS SECTION - AFTER

FLOODPLAIN LATERAL FLOW ANALYSIS

Lower Rio Grande Valley
By Greg Gentsch, P.E. September 30, 2019

 Sheet 5 of 6

10 foot wide Utility strip
25 foot wide Roadway & Multi-use pathway

FLOODPLAIN LATERAL FLOW ANALYSIS

Lower Rio Grande Valley
By Greg Gentsch, P.E. September 30, 2019

 United States

Sheet 6 of 6

Velocities at the 5” openings
will average below 1 ft./sec

Velocities on the Floodplain
are all below 1 ft./sec

RIO GRANDE MAIN CHANNEL

RIO GRANDE IMPROVED FLOW

BOLLARD FENCE PLAN VIEW

FLOODPLAIN LATERAL FLOW ANALYSIS

Lower Rio Grande Valley
By Greg Gentsch, P.E. September 30, 2019