BW - CHAPTER 14: CASE STUDY- NEOSHO RIVER,

ALLEN COUNTY, (MIKE GEFFERT’S PROPERTY)

SOUTHEAST KANSASConstructed May-July 2000 Using Bendway Weirs for thalweg

realignment & bank erosion reduction

Neosho River Project Specifications• River is 260 ft wide

• Gravel-sand bed

• Project is 2,200 ft long, Outer bank is 25 ft tall, it eroded 178 ft laterally in 6 years time

• 11 Bendway Weirs, are all 70 ft long, spaced 210 ft apart & constructed of “shot rock”, 400 lb max.

• First set of velocities (March 15, 2001) water was 6 ft over the weirs, second set of velocities (Mar 16, 2001) water was a measured 12 ft over the top of the weirs!!

• Velocities were measured with floating oranges

Pre-Project. Looking upstream at the near vertical eroded bank

PRE-PROJECT-NEOSHO RIVER @ GEFFERT’S-PIX BY PHIL BALCH 8/25/99

Keyway for Bendway Weir doubling as a haul road.

CONSTRUCTION-NEOSHO RIVER @ GEFFERT’S- PIX BY PHIL BALCH 5/23/00

Placing key stone in the keyway.

CONSTRUCTION-NEOSHO RIVER @ GEFFERT’S- PIX BY PHIL BALCH 5/23/00

Dozier pushing stone to form Bendway Weir #3. Note the thalweg is already being moved toward the center of the channel by the upstream weirs.

CONSTRUCTION-NEOSHO RIVER @ GEFFERT’S- PIX BY PHIL BALCH 5/30/00

1 YEAR LATER-NEOSHO RIVER @ GEFFERT’S-PIX BY PHIL BALCH 5/01

1 year later. Looking DS at the Neosho River on the flood

2 YEARS LATER-NEOSHO RIVER @ GEFFERT’S-PIX BY PHIL BALCH 9/2002

2 years later. Looking US @ Bendway Weirs & stable bank

2 YEARS LATER-NEOSHO RIVER @ GEFFERT’S-PIX BY PHIL BALCH 9/2002

2 years later. Looking US at Bendway Weirs & stable bank

3 YEARS LATER-NEOSHO RIVER @ GEFFERT’S-PIX BY PHIL BALCH 9/6/2003

3 years later. Looking US at stable bank

HIGH WATER – LET’S GET SOME

VELOCITIES(We have a sack of oranges

& time on our hands)

Mini case study: 1 of 3

Neosho River, Allen County, Kansas 6 ft of

water over weirs (estimated) Top water velocities within the weir field never exceeded

1.00 ft/second

BW #7

BW #3

BW #11

1.61

0.602.041.03

0.332.792.72

Data collected March 15, 2001

The Thalweg left the bank a measured 200

ft US of BW#1

The Thalweg hit the bank a measured

150 ft DS of BW#11

Looking US at weirs at low water on the Neosho River, KS. This is not when the velocity data was taken.

Mini case study: 2 of 3

Mini case study: 3 of 3

Neosho River, Allen County, Kansas 12 ft of

water over weirs (measured) Top water

velocities within the weir field never exceeded 3.00

ft/second

BW #7

BW #3

BW #11

2.886.47

6.08

2.924.074.97

2.634.544.64

Data collected March 15, 2001

SINCE PROJECT CONSTRUCTION THE

RIVER HAS BEEN OUT OF BANK SEVERAL TIMES - IN JULY 2007 THE RIVER

EXPERIENCED THE 100 YEAR FLOOD

7 YEARS LATER-NEOSHO RIVER @ GEFFERT’S-PIX BY PHIL BALCH 11/9/2007

7 years later. Looking US. Note deposition between weirs.

AFTER A 100 YEAR FLOOD-NEOSHO RIVER - PIX BY DERRICK 12/11/2008

8 years later. After a 100 year flood. Looking US @ the Bendway Weirs & snow

AFTER A 100 YEAR FLOOD-NEOSHO RIVER - PIX BY DERRICK 12/11/2008

8 years later. After a 100 year flood. Looking DS @ the Bendway Weirs

AFTER A 100 YEAR FLOOD-NEOSHO RIVER - PIX BY DERRICK 12/11/2008

8 years later. After a 100 year flood. Looking DS @ lower end of the bend

AFTER A 100 YEAR FLOOD-NEOSHO RIVER - PIX BY DERRICK 12/11/2008

8 years later. After THE 100 YEAR FLOOD. Looking DS. Erosion has laid the bank back to a stable angle. Note how flat the bank is at the toe

AFTER A 100 YEAR FLOOD-NEOSHO RIVER - PIX BY DERRICK 12/11/2008

After a 100 year flood. Looking DS. Large Woody Debris is indicative of slower velocities & good for aquatic habitat.

This PowerPoint presentation was developed & built by Dave Derrick.

Any questions or comments, call my personal cell @ 601-218-7717, or email @ d_derrick@r2d-eng.com

Enjoy the information!!