2577Soil Bioengineered Systems

2577.1DESCRIPTION

This Work consists of installing vegetation with geosynthetic or natural Materials to stabilize areas susceptible to erosion. The Contractor may use soil bioengineering as a permanent soil stabilization system in ditches, along stream banks, on shorelines, or on slopes . This Work also consists of providing and installing a composite system on the Project.

2577.2MATERIALS

2577.3CONSTRUCTION REQUIREMENTS

A General The installation locations and layouts shown on the P lans are approximate. The Engineer will determine the exact locations and layouts of bioengineered systems. Provide a qualified nurseryman, landscape specialist, or experienced crews working under the direct supervision of a qualified nurseryman or landscape specialist to harvest and install plant Material.

Do not begin planting operations or deliver planting stock to the P roject until the Engineer determines that weather and soil conditions are suitable for planting and preparations for planting are complete. During placement, install components until complete. Prevent overnight drying out of plant stock by storing in water. On slopes, begin installing Material at the bottom of slope and proceed in horizontal layers upward. On shorelines and banks, begin installing Material below the water line and proceed up the bank. During the Work, prevent siltation and turbidity of flowing or impounded waters of the State . If working in water, protect the Work site with curtains, barriers, or other containment devices to prevent sediment and debris from entering the receiving water body. B Harvesting Plant Stock Obtain plant stock and cuttings from the regions, zones, or both shown on the P lans. At least three Working Days before harvesting planting stock for the Project, notify the Engineer of the harvest date to allow for inspection. C Season of Placement Refer to Table 2577.3-1 for the dates for seasonal placement. The Engineer may adjust a date specified in Table 2577.3-1 by no more than 20 Calendar Days, based on the prevailing weather conditions. Provide plant Material in a dormant stage; before buds burst open in the spring or after leaves change color and drop in the fall. Table 2577.3-1 Approximate Season of Placement System Spring Fall Wattling Before April 15 After Nov 1 Brush Layering Before April 15 After Nov 1 Live Stake Before April 15 After Nov 1 Root-Rap April 15 – June 10 July 20 – Sept 20 D Wattling Dig trenches along the contours of the slope, place bundles of dormant plant cuttings into the trenches, and tamp loose soil over the bundles. Before trenching, drive wooden stakes 16 inches on center along each trench location. Provide stakes with a diameter of 2 inches and a length of 2 feet. Drive the stakes to a firm hold with the tops 6 inches above grade. Dig trenches no more than 1 hour before installing plant Materials to minimize drying of soils. Leave the overall soil surface in a rough condition with clods, and ridges for maximum resistance to erosion. Immediately following trenching, place bundles of dormant plant cuttings into the trench . Lay cuttings in bundles together with the butt ends located at alternate ends of the bundle and tightly tied with binder twine at least 3 points along the bundle. Provide bundles consisting of dormant woody cuttings from 3/8 inch to 2 inches in diameter and from 3 feet to 8 feet long. Provide bundles from 6 inches to 8 inches in diameter. Overlap wattle ends in the trench. Drive additional stakes through bundles at a spacing no greater than 2 feet on center. During placement of the bundles, cover the bundles with loose soil, working it into the wattles leaving a uniform fringe of plant Material , exposed to a height from 2 inches to 3 inches.

E Brush Layering Make trenches along the contour of the slope and embed dormant green plant cuttings into the slots and tamp loose soil over the cuttings. Make trenches 2 feet deep, angled downward into the slope. Provide plant cuttings consisting of stems 3 feet long, and from 1/2 inch to 2 inches in diameter. Transport cuttings in containers of water and keep cuttings in the containers until installation . As soon as possible after making the trenches, place the plant cuttings into the trenches with the butt end placed into the trench and at least 6 inches of the cuttings protruding out of the trench. Place the stems randomly with some crisscrossing. While placing plant cuttings, immediately backfill the trench cuttings with soil and firm the backfill to meet the Engineer’s approval. F Live Stakes Insert dormant live cuttings into the soil and tamp soil lightly around the cutting . Provide cuttings consisting of stems at least 3 feet long and from 1 inch to 2 inches in diameter. Transport cut Material in containers of water and keep Material in water until installation. Insert the bottom end of the cuttings so the bottom-end is at right angles to the slope face for at least 2/3 to 3/4 of the cutting length and tamp. Do not split the ends or damage the bark of the cuttings. Place cuttings 2 feet on center, using a triangular spacing. Place cuttings at a density of 2 to 4 stakes per square yard. If riprap is less than 2 feet thick, stake the riprap (joint planting). Make a pilot hole by driving a tool, such as a pry bar or rebar, through the riprap and filter Layer, to reach the ground soil. Use a dead blow hammer to tamp the cuttings and avoid damaging the bark . Place the cuttings in a random configuration 2 feet on center. G Placing Coir log Place sediment control log type coir for stabilizing shorelines. Before installing the coir log, drive wooden stakes with a diameter of 2 inches and a length of 3 feet, 1 foot on center along the planned alignment of the coir log. Ensure the stakes extend from 8 inches to 10 inches above the elevation of the water surface shown on the Plans. After placing the stakes, install the coir log so the upper surface of the coir log is parallel to the water surface and 2 inches protrude above the normal water level. Lace coir logs together end to end with woven nylon twine, 1/8 inch in diameter to create a continuous length. Bury both ends of the coir rolls 5 feet laterally into the bank. H Root-Rap Place a soil filled riprap liner, and overseed or plant vegetation in accordance with the details, typical sections, and elevation controls as shown on the Plans. The Engineer will stake the actual alignment. During the Work, continuously place the granular channel lining or riprap and shape the channel. Begin seeding or planting within 48 hours of shaping the channel or as required by Contract. I Root Wad Place a large tree trunk with root attached for stabilizing higher velocity river and stream banks. Tree trunk shall be a minimum diameter of 12 inches and length of 14 to 20 feet with attached roots. Provide footer boulders between 350 to 450 pounds and 24 to 30 inches diameter in accordance to Specifications 3601, “Riprap Material.” Support root wad with footer log, bury footer boulder to support root wad, and bury tree trunk into stream bed, root end facing stream. Top of root wad shall be at bank full elevation and tree trunk should be angled down at a slope of 1:6 (Vertical:Horizontal) into the bank. J Acceptance of Work Upon satisfactory installation of the bioengineered systems, the Engineer will authorize partial payment not to exceed 80 percent of the Contract Unit Prices. The remaining percentage shall not become due and payable until after the 30-day maintenance period.

K Workmanship and Quality To qualify for payment, perform corrective actions when the quality and workmanship fails to meet the Material, installation, or maintenance requirements in the Contract.

2577.4METHOD OF MEASUREMENT

A Wattling The Engineer will measure Wattling by the linear foot of each trench made and planted. If several trenches are made and planted, the Engineer will add each length of trench planted and accepted to the total. B Brush layering The Engineer will measure Brush layering by the linear foot of each horizontal trench made and planted. If several trenches are made and planted, the Engineer will add each length of trench planted and accepted to the total. C Coir log The Engineer will measure Coir log by the linear foot provided and installed including buried portions. D Root Wad The Engineer will measure Root wad by the each installed including the footer log and footer boulder. E Root rap The Engineer will measure Root rap by the cubic yard and includes the riprap and topsoil Material. Seeding and stabilization will be measured separately.

2577.5BASIS OF PAYMENT

The Contract Pay Item for Bioengineering systems will include all labor, Materials, Equipment, and other Incidentals to compete the Work. For items of Work not included in the schedule of Contract Pay Items, the Department will pay Unit Prices for the relevant items of Work. If the Contract does not include Pay Items for bioengineered systems, the Department will pay for bioengineered system items as Extra Work in accordance with 1402, “Contract Revisions.” A Wattles The costs of plant cuttings, bundles, and stakes and rope to fasten logs are included in the Contract Unit Price for Wattling. B Brush Layering The costs of plant cuttings and stakes and rope to fasten logs are included in the C ontract Unit Price for Brush layering. C Coir Logs The costs of stakes and rope to fasten logs are included in the Contract Unit Price for coir logs.

D Schedule The Department will pay for bioengineered system items on the basis of the following schedule: Item No Item Unit

2577.502 Live Stakes each

2 Root Wad each

3 Brush Layering linear feet

3 Wattling linear feet

7 Root Rap Cubic yard