site 6 – delaware river right bank blow-out up the hill from the delaware river (swirling river...

SITE 6 – DELAWARE RIVER RIGHT BANK BLOW-OUT UP THE

HILL FROM THE DELAWARE RIVER

(SWIRLING RIVER EROSION & GROUNDWATER PIPING) DELAWARE WATER GAP

NATIONAL RECREATION AREA NATIONAL PARK SERVICE PROJECT CONSTRUCTED

SEPTEMBER 10-15, 2009

PROBLEMS This bowl-shaped upper bank blow-out appears to have

been initially eroded by river flows guided into the area by a jam of large downed trees at the toe of the right bank (see next slide). The swirling water eroded the bank leaving a circular failure with steep banks.

Additional erosion has been caused by flood waters draining back into the eroded area from the surrounding fields during high water events.

A third stressor is groundwater piping exiting the eroding bank at an old stream location. The stream was rerouted decades ago. Water seeps from the active failing bank.

The actively eroding bank is failing in an uphill direction & presently threatening an important archeological site.

Aerial view of project area with work limits

delineated.

Note Large Woody debris (LWD) in river

that vectored river energy into the bank causing the bank to

initially erode.

Courtesy of Ecological Restoration, Inc.

PRE-PROJECT PHOTOS

by Dave Derrick

July 23, 2008, Dec. 15, 2008, & Sept. 9, 2009

From top bank, looking downhill at the blow-out area.

PRE-PROJECT DELAWARE RIVER-SITE 6 - PIX BY DERRICK 7-23-2008

Looking north, this area has decent native grasses.


Vertical eroding scarp is masked by vegetation.


Looking uphill (west) at eroding bank, gully & escarpment.


Looking uphill (west) @ the eroding escarpment partially caused by groundwater seepage.


Escarpment & erosion is easier to see during winter

PRE-PROJECT DELAWARE RIVER-SITE 6-PIX BY DERRICK 12-15-2008

Looking uphill (southwest) @ escarpment & eroded bank.


Looking south @ escarpment & bank erosion.


THE PLAN

SOLUTIONS (THE PLAN) This project is designed to stabilize the bank at the

present location by using “soft” stabilization methods. Banks will be sloped and a sloping 12 inch thick gravel French drain installed. The drain will be covered with geotextile and a foot thick layer of topsoil. Native grasses will be seeded in all disturbed areas & over the French drain. A 100% coir Erosion Control Blanket will be installed over the soil with many species of rooted stock shrubs installed at the top and bottom of the French drain. At the toe of the slope two rows of coir logs will be installed with two rows of rooted willow & dogwood whips, & unrooted willows planted in between.

On the lower river bank, 3 rows of rooted willow whips will be installed to bridge a gap in the existing riparian corridor & reduce the chance of high river flows from again swirling into the repaired bank area.

Courtesy of Ecological Restoration, Inc.

CONSTRUCTION PHOTOS

by Dave Derrick, September 10-14, 2009

A follow-the-river hiking path had just been completed at the project site. We used a portion of the path for access.

CONSTRUCTION DELAWARE RIVER-SITE 6-PIX BY DERRICK 9-10-2009

PLANTS PLANTED

Fragrant Sumac 27 3 gallon pots Silky Dogwood 400 bare root & cuttings Black Willow 1210 cuttings & tree bands Ninebark 9 3 gallon pots Nannyberry 57 1 gallon pots Arrowwood 56 1 gallon pots Grey Dogwood 27 3 gallon pots

Common Name # Size

TRENCH PLANTING

ROOTED-STOCK WILLOW WHIPS DOWN BY THE

RIVER

Looking downhill @ mini trackhoe digging a trench for the rooted-stock willow whips.


NARROW TRENCH PLANTING TECHNIQUE

Dig the trench.

Spoil


Place the last scoop of dug soil back in the trench so plantings

are in loose material.

Spoil

Looking DS @ the trench closest to the river & two flats of willow whips. Three trenches parallel with the river will be dug & planted with willow to tie into the existing US & DS forested riparian buffer.



Place rooted-stock willow whips into

loose soil in trench. Lean whips against side of trench away from the spoil pile

Spoil

Rooted-stock Black Willow whips in tree bands (small pots)


Willows are 6 months old, cuttings were planted in a 2.75 inch by 2.75 inch by 6 inch pot in March (now 4-6 ft tall, approx.½ diameter)


Close-up of rooted-stock Black Willow whips in trench.


Whips in trench, planted at a rate of three whips per foot.



Water plants in &

backfill.

Mini-excavator backfilling trench, which plants the willows.


Looking DS. The trench closest to the river is keyed up & into the existing riparian forest @ both the US & DS ends.


Looking DS @ the uppermost of the 3 trench plantings.


Close-up of the trench willow plantings. Good sandy soil.


Looking DS @ all 3 parallel willow trenches & silt fence.


TRENCH PLANTING THE ROOTED-STOCK WILLOW WHIPS DOWN BY THE

RIVER IS COMPLETE !!

NEXT ARE THREE SETS OF PIX OF THE FRENCH DRAIN AREA

LOOKING NORTH, EAST, & SOUTH.

PIX ARE PRE-PROJECT,

CONSTRUCTION, & POST-PROJECT

THE FRENCH DRAIN, WITH

GEOTEXTILE, SOIL, NATIVE GRASS SEED, & COIR

MATTING (LOOKING NORTH)

Looking north @ the eroded, unstable bank.


An archeological dig was undertaken at the eroding bank. We understand nothing of significance was found. This was filled with the 3 inch gravel filter material to form a chimney drain.


Looking north. Bank sloped with the mini tracked loader.


SUITABLE STONE

For the “French drain’ sloped filter a 1 ft thick layer of 3 inch poorly sorted gravel was used.


Looking north. Spreading filter gravel with the mini loader.


Gravel staged down over sloped bank.


Gravel spread, ready for the geotextile separator. Mound at top bank will not allow rainwater to gully down new slope.


Geotextile will be tucked in @ sharp edge @ top bank.


Rolling geotextile over filter. Twelve inches of soil has been placed over the geotextile in the foreground.


Geotextile key trenched at top & partially covered @ toe.


Looking north @ 12’ soil cover over geotextile. Seeding next. Trenches at bottom will be planted with willow & dogwood.


Cutting coir blanket to length plus close-up. This is a 700 series (700 grams per sq. meter blanket. Heavy& tough. Traps soil & seed well,

sticks in dirt when wet, open weave, can be reseeded if needed


Looking north. 100% coir Erosion Control Blanket covers soil & seed. Two trenches at toe planted with Black Willow & dogwood.


Close-up of trench plantings & trenched-in toe of coir ECB.


CONSTRUCTION COMPLETEPhotos by

Dave Derrick SEPT. 18, 2009

CONSTRUCTION COMPLETE-DELAWARE R-SITE 6-DERRICK 9-18-2009

CONSTRUCTION COMPLETE-Looking north @ top bank

5 DAYS AFTER PROJECT

COMPLETIONPhotos by Derrick SEPT. 23, 2009

5 DAYS LATER-Looking north @ top bank.

5 DAYS LATER - DELAWARE RIVER-SITE 6-PIX BY DERRICK 9-23-2010

5 DAYS LATER-Looking north. Note cover crop grass growing through coir matting. Native grass will germinate spring 2010.


5 DAYS LATER-Looking north @ top, slope, & toe.


5 DAYS LATER-Looking north @ toe. Unrooted willow leaves have withered, while rooted willow poles are robust.


THE FRENCH DRAIN WITH GEOTEXTILE,

SOIL, SEED, AND COIR MATTING (LOOKING EAST)

Looking east. Sloping bank with the mini tracked loader.


Sloping & grading bank. Filter gravel staged.


Looking east. Spreading filter gravel with the mini loader.


Geotextile in place, some soil staged.


Upper edge of geotextile is tucked in @ vertical face of gravel.


Looking uphill @ staged soil on geotextile.


Looking uphill. Ready to roll geotextile downslope.


Looking downhill @ 12” layer of soil over the geotextile. Site is now ready to be seeded & 100% coir Erosion Control Blanket (ECB) laid out & anchored down.


Looking east. Site has been seeded. Coir mat is now being installed. Note key trench for ECB @ toe of slope.


Looking east @ upper key trench for coir matting (ECB).


Looking east. Rolling coir & anchoring with wire staples.



Completed slope filter, geotextile, soil layer, seed, & ECB with two rows of narrow trench dogwood & willow rooted poles & 2 coir logs

Coir logs tied into hillside @ DS end.


Looking downhill @ upper bank riparian plantings.


CONSTRUCTION COMPLETE-DELAWARE R.-SITE 6-DERRICK 9-18-2009

CONSTRUCTION COMPLETE-Looking east @ top bank & slope

5 DAYS LATER-Looking east @ top bank plantings.


5 DAYS LATER-Looking east @ cover crop grass growing through the coir Erosion Control Blanket.


5 DAYS LATER-Looking east @ top, slope, & toe.



5 DAYS LATER-Looking @ toe. Rooted willow poles are robust while unrooted willow pole leaves have withered.

THE FRENCH DRAIN WITH GEOTEXTILE, SOIL, SEED, AND COIR MATTING -

LOOKING SOUTH (FROM UPSTREAM

LOOKING DOWNSTREAM)

Looking south @ sloped bank & completed gravel filter, with a portion covered with geotextile & 12” soil layer.


Looking south @ sloped bank & completed gravel filter, with a portion covered with geotextile & 12” soil layer


Looking south, French drain & geotextile in. Some areas the soil layer, seed, & ECB has been installed.


Vegetation in center was left alone as many high quality native grasses are populating that area.


All slope work is complete, trench plantings in at toe.


Looking south @ completed slope.



CONSTRUCTION COMPLETE-Looking south @ top bank plants.


CONSTRUCTION COMPLETE-Looking south @ top bank plants, and top bank mound that will guide rain water away from slope


CONSTRUCTION COMPLETE-Looking south @ completed slope filter, geotextile, soil layer, seed, & ECB with two rows of narrow

trench dogwood & willow rooted poles & 2 coir logs.


CONSTRUCTION COMPLETE-Coir logs keyed up slope


CONSTRUCTION COMPLETE-Close-up of plants @ toe.


CONSTRUCTION COMPLETE-Looking south @ toe.


CONSTRUCTION COMPLETE-Looking south @ the project


CONSTRUCTION COMPLETE-Looking south @ the overall project

5 DAYS LATER-Looking south @ top bank.


5 DAYS LATER-Looking south @ top bank & slope. Note cover crop grass growing through coir mat.


5 DAYS LATER-Looking south @. Top, slope, & toe. Note mound at top slope to prevent overbank flow down slope


5 DAYS LATER-Looking south @ project & native grasses in center that were not disturbed.


5 DAYS LATER-Filling ruts in haul road.


TOTALLY FINISHED

1 YEAR AFTER PROJECT

COMPLETION Photos by

Dave DerrickSEPT. 12, 2010

1 YEAR LATER-Looking US @ the US end of one of the rows of willows. So much other growth, hard to find willows, time will tell. Entire project was well vegetated & very stable, very little sediment.

1 YEAR LATER-DELAWARE R.-SITE 6 PIX BY DERRICK 9-12-2010

1 YEAR LATER-Looking east at toe of south slope. Decent growth, rooted-stock willows did better than unrooted poles. Very little sediment by coir logs.


1 YEAR LATER-Something is tearing up the 100% Coir logs, but they have served their purpose. Very little

sediment came off of the slopes, which is good!!


1 YEAR LATER-Looking north @ west slope. All sections well vegetated & stable. Willow growth is decent.


1 YEAR LATER-Looking @ coir logs & willows. All vegged, all stable (bottom, slopes, & top bank), no slope movement.


1 YEAR LATER-Looking north @ west & north slopes. All vegged, all stable, no slope movement, very little sediment.


1 YEAR LATER-Looking south @ west slope. All vegged, all stable, no slope movement, very little sediment.


1 YEAR LATER-Looking southwest. All vegged, all stable, no slope movement, very little sediment.


1 YEAR LATER-Looking @ west slope. All vegged, all stable, no slope movement, very little sediment.


1 YEAR LATER-Looking toward the river. All vegged, all stable, no slope movement, very little sediment.


This PowerPoint presentation was developed & built by Dave Derrick.

Any questions or comments, call my personal cell @ 601-218-7717, or email @ [email protected]

Enjoy the information!!

mailto:[email protected]

CONSTRUCT-LIVING DIKES-DINGMANS CR. PIX BY DERRICK 9-25-09

#1 Saints fan!!

site 6 – delaware river right bank blow-out up the hill from the delaware river (swirling river...

Documents

eroding bank

escarpment bank

river energy

river flows

project photos

planthis project

eroded area

active failing bank