ACCOTINK CREEK @ AIRFIELD RUNWAY &

RECHLORINATION PLANT PROJECTS GARRISON FORT

BELVOIR, FAIRFAX, VACONSTRUCTED

Dec 2-5, 2008

LONGITUDINAL PEAKED STONE TOE PROTECTION (LPSTP) Built with Virginia DOT Class II stone,

level-crested @ 3 ft above the base-flow water surface elevation & trenched 3 ft into the bed.

One row of live willow poles (3 poles/ft) planted in the LPSTP & another row (3/ft)

laid on top of LPSTP (termed Live Siltation).

STEP-BY STEPS FOR ACCOTINK

CREEK, FT. BELVOIR, VA

Toe-down Enhanced LPSTP

All drawings by Dave Derrick

Typical cross-section for Accotink Creek in the proposed project area

ACCOTINK CREEK, FT. BELVOIR, VA LOOKING UPSTREAM

Dig toe-down section of LPSTP 3 ft below bed of stream

ACCOTINK CREEK, FT. BELVOIR, VA

ACCOTINK CREEK, FT. BELVOIR, VA

Place Longitudinal Peaked Stone Toe Protection

(LPSTP) stone in trench

Looking across @ close up of LPSTP stone.

CONSTRUCTION-ACCOTINK CR.-RECHLORINATION - DERRICK 12-2008

ACCOTINK CREEK, FT. BELVOIR, VA

Place Joint Planting (live willow poles) on top of stone (angled up at least 20 degrees) at the rate of

3 poles per lineal foot.

Looking across @ willow poles on stone. Placing soil on poles.

CONSTRUCTION-ACCOTINK CR.-RECHLORINATION- DERRICK 12-2008

ACCOTINK CREEK, FT. BELVOIR, VA

Place Live Siltation (willow poles) on top of stone at the rate of 3 poles per lineal foot

Looking US. LPSTP with joint plantings & Live Siltation in place

CONSTRUCTION-ACCOTINK CR.-RECHLORINATION- DERRICK 12-2008

ACCOTINK CREEK, FT. BELVOIR, VA

At 35 ft spacing intervals, stone Bendway Weirs will be installed that will move the thalweg away

from the toe of the LPSTP.

LPSTP with Joint Pole Plantings &

Live Siltation with an Erosion Control

Blanket

ACCOTINK CREEK, FT. BELVOIR, VA

Tuck the Erosion Control Blanket (ECB) at base of

slope.

The ECB used here is a 100% coir (Coconut fiber)

Rolanka BioD-Mat 40

Roll ECB out over willows & LPSTP

stone.

Install Living Dikes midway between

mid-project keys, 3 deep-planted Live

Willow Poles per ft.

Hoe starting to dig trench for Living Dike (perpendicular to direction of high flow)

CONSTRUCTION-ACCOTINK CR.-RECHLORINATION- DERRICK 12-2008

Looking downhill @ Living Dike trench with willows installed & partially backfilled.

CONSTRUCTION-ACCOTINK CR.-RECHLORINATION - DERRICK 12-2008

Looking downhill @ Living Dike trench with willows installed & partially backfilled. Leave bank rough. Ready for ECB.

CONSTRUCTION-ACCOTINK CR.-RECHLORINATION- DERRICK 12-2008

ACCOTINK CREEK, FT. BELVOIR, VA

FIL

L

CUT

Slope bank. A balanced cut/fill in some sections, heavily eroded areas required soil backfill. Backfill anchors the ECB.

Looking US @ erosion control blankets with soil covering the bottom end

CONSTRUCTION-ACCOTINK CR.-RECHLORINATION - DERRICK 12-2008

Looking US @ coir blanket & Bendway Weirs in place.

CONSTRUCTION-ACCOTINK CR.-RECHLORINATION - DERRICK 12-2008

ACCOTINK CREEK, FT. BELVOIR, VA

Install rooted stock plants through ECB as appropriate

Looking US @ workers installing rooted plants thru ECB.

CONSTRUCTION-ACCOTINK CR.-RECHLORINATION - DERRICK 12-2008

Looking US @ coir blanket, Living Dikes & rooted plants.

CONSTRUCTION-ACCOTINK CR.-RECHLORINATION - DERRICK 12-2008

CONSTRUCTION COMPLETE-Looking US nine months after completion. Most willows browsed by beaver

CONSTRUCTION COMPLETE-ACCOTINK CR.-DERRICK 9-13-2009

Man’s best friend, Cleophus Speed Elvis Derrick