Attach_2_Specs_Plans.docx

ATTACHMENT 2

STREAM RESTORATION SPECIFICATIONS

EQUIPMENT AND OPERATOR SPECIFICATIONS

A) Manner of Construction - Excavation will be done in a manner which will minimize sedimentation in the stream channel. Silt fence will be installed downstream of the construction area to reduce the risk of sediment entering the stream.

B) Equipment Operator Performance - Equipment operators shall be experienced and competent in the use of the equipment to which they are assigned. They shall be expected to demonstrate a level of proficiency with the equipment which enables them to be productive in all aspects of stream restoration work. Equipment operators shall be experienced in the construction of Rosgen designed structures; including the cross vane, J-hook vane, and Toe-wood/Sod mat.

Operators will be instructed by the construction inspector as to the desired result of construction activities. Operators will be responsible for determining how best to use equipment to achieve the desired results. Chain saw operators will be required to cut trees, limbs and root masses as necessary to facilitate the removal and placement of debris in the stream.

C) Environmental Considerations - Earth moving equipment will cross and operate in the stream flow only when necessary and only when directed to do so by the construction inspector. Equipment shall be new or of low hours and be maintained to prevent fuel, oil and lubricant spills in the vicinity of the stream. Refueling, repairs and lubrication will be performed at a safe distances from the stream and only at locations approved by the construction inspector where water is controlled by runoff control measures.

D) Safety Considerations - At work sites, where equipment will be operated on Forest Roads, flagman shall be stationed to warn oncoming traffic of congestion. Construction road signs shall be in place and a means of removing sediment, mud or rocks from roadways shall be established. The contractor will be responsible for the implementation of these measures.

E) Equipment Specifications

Hydraulic Excavator:

· Track mounted, hydraulic powered.

· Excavator:

· Min weight – 30,000 lbs

· Min. Reach – 22 feet

· Min Digging Depth – 20 feet

· Min Bucket size – 1.0 Cu Yd.

· Min 115 HP

· Equipped with hydraulic thumb, with experienced operator as described above.

(More than 1 excavator may be required. Unit price bid should be for one excavator for one hour of running time).

IN-STREAM STRUCTURES SPECIFICATIONS

Structure Stone Description The work covered by this section consists of furnishing, stockpiling, placing and maintaining approved stone to be utilized to construct rock and log vanes, root wad structures, the step-pool structures, stream crossings, sediment and erosion control measures for use in locations as directed by the Designer. The quantity of stone may be increased, decreased, or eliminated entirely at the direction of the Designer. Such variations in quantity will not be considered as alterations in the details of construction or a change in the character of the work.

Materials Stone for Coarse Aggregate, No. 57 Stone, "Rip Rap-Class B", and "Boulder" shall consist of blasted stone or other stone approved by the Designer. The stone shall be sound, tough, dense, resistant to the action of air and water, and suitable in all other respects for the purpose intended.

All stone shall meet the approval of the Designer. While no specific gradation is required, the various sizes of the stone shall be equally distributed within the required size range. The size of an individual stone particle will be determined by measuring its long dimension.

Acceptance Criteria for Stone

CLASS

REQUIRED STONE SIZES (INCHES)

Minimum

Average

Maximum

B

Boulder 36" x 20" x 12"

No more than 5 percent of the material furnished can be less than the minimum size specified, more than 10 percent of the material can exceed the maximum size specified. Boulders shall be relatively flat on either side in the same dimension, preferably the long dimension.

Construction The Contractor shall place stone, in locations shown on the construction plans to the thickness, widths, and lengths as shown on the construction plans or directed by the Designer. All stone shall be placed neatly and uniformly with an even surface to form an in-stream structure or a sediment and erosion control device or in accordance with the construction plans and special provisions, and shall meet the approval of the Designer.

Method of Measurement The quantity of stone required to construct the structures or sediment and erosion control measures detailed in these special provisions will be incidental to those bid items. However, field conditions may warrant the need for additional stone greater than the quantity specified or detailed for each bid item. The quantity of stone that has been incorporated into the project, as directed or approved by the Designer, which exceeds 110% of the quantity required for each bid item will be measured by weight. Measured by weight will require the quantity to be weighed in trucks on certified platform scales. Stone that was previously stockpiled for other bid items will not be measured a second time for this provision.

Basis of Payment When field conditions dictate the need for additional quantity greater than 10% of the bid item, the quantity of stone measured as provided above, will be paid for at the contract unit price per ton for "Misc. Coarse Aggregate, No. 57 Stone", "Misc. Rip Rap-Class B", and "Misc. Boulder". Such price and payment will be full compensation for all work covered by this section, including but not limited to furnishing, weighing, stockpiling, re-handling, placing, and maintaining the stone and disposal of any materials not incorporated into the project if directed by the Designer.

Payment will be made under:

Misc. Coarse Aggregate, No. 57 Stone.......................................................................................TON Misc. Rip Rap-Class B............................................................................................................TON Misc. Boulder..........................................................................................................................TON

Rock J-hook & Cross Vane Description Rock J-hook and Cross Vanes are primarily used for grade control. These structures serve to maintain the integrity of the upstream riffle while promoting scouring in the downstream pool. The design shape is roughly that of the letter "J" or “U” with the apex located on the upstream side at the foot of the riffle. Footer boulders are placed in the channel bottom for stability. Header boulders are then placed on top of these footer boulders. Header boulders in the middle of the channel are at approximately the same depth as the riffle. For the J-hook, on one side of the channel, wing boulders are placed at an angle to the stream bank, gradually inclining in elevation until they are located near the bankfull surface directly adjacent to the stream bank. On the other side, the structure turns downstream to create the hook of the “J”, matching the slope of the wing until it goes directly toward the bank as a sill. Water flowing downstream is forced over these boulders towards the middle and opposite side of the channel, effectively turning flow and scouring out a pool below. Boulders placed at the apex hold back streambed material and prevent it from washing downstream.

The quantity of Rock J-hook Vanes may be increased, decreased, or eliminated entirely at the direction of the Designer. Such variations in quantity will not be considered as alterations in the details of construction or a change in the character of the work (See Rock J-hook Vane detail below).

Materials All materials shall meet the requirements of boulder as outlined in Special Provision "Structure Stone". Back fill material shall be obtained from the stream channel bed, likely from the constructed pool. Large woody debris may be incorporated into the structure as directed by the Designer.

Installation A trench shall be dug in such a manner that the footer boulders, the hook header boulders and at least 1/3 of the wing boulders are buried beneath the bed surface elevation. Refer to the construction plans for exact installation guide and locations of vane to be installed. An excavator, with a bucket that includes a hydraulic thumb, shall be used to place boulders under the supervision of Designer. Footer boulders shall be placed first with header boulders placed on top prior to any back filling of the trench. Boulders shall be selected and positioned such that they butt tightly together and there are multiple contact points between all boulders (flat smooth surfaces that fit together). Gaps between boulders shall be filled (chinked) with a combination of class A and No. 57 size stone found on site until plugged. In the center portion of the channel (vane invert), the header boulder shall be placed with gaps between the rock with the top of the header boulder at an elevation designated by the Designer. The header boulders in the side, or wing, portion shall be placed in such a manner as they slope up from bed elevation to bankfull or below at a 2 to 7 percent slope or as shown in detail. Header and footer boulders at both banks shall be tied in securely to the bank in such a way that eliminates the possibility of water diverting around them. A rock sill shall be utilized to further prevent water from cutting around the structure. The area between the stream bank and vane on the upstream side of the structure will be backfilled with stream bed material.

Structures shall be built to the approval of the Designer. The Designer may adjust the number and placement of structures in the field.

Basis of Payment Payment for installation of Rock J-hook Vane shall be as outlined. This payment shall be considered full compensation for all labor, equipment, hauling, placing, handling, sorting, fitting, materials, and incidentals necessary to construct the rock vane.

Payment will be made under:

Equipment & Labor…………………………………….…………………………..………..……..HOURS Materials:

Boulders………………………………………………………………………………….……..TON

Log Vane

Description This structure serves to decrease stress in the near-bank region while promoting scouring in the downstream pool. Logs are placed at an angle to the stream bank, gradually inclining in elevation until they are located near ½ bankfull elevation directly adjacent to the stream bank. Water flowing downstream is forced over these logs towards the middle of the channel, effectively scouring out a pool below. The quantity of log vanes may be increased, decreased, or eliminated entirely at the direction of the designer. Such variations in quantity will not be considered as alterations in the details of construction or a change in the character of the work.

Materials Trees to be used for the vane shall be provided by the Forest Service from near the site. All log materials shall be at least 10 inches in diameter. A sheet of non woven geotextile fabric (4oz. or greater) shall be placed the length of the vane arm on the upstream side, stapled to the top log in a manner that they will be covered by back fill material. Back fill material shall be obtained from the stream channel bed.

Installation A trench shall be dug in such a manner that the footer and header logs are buried beneath the bed surface elevation at least three feet. An excavator, with a bucket that includes a hydraulic thumb, shall be used to place logs under the supervision of Designer. Logs shall be tightly sealed with no gaps between the header and footer log. Filter fabric shall be placed on the upstream side of the structure and backfilled with materials excavated on-site to prevent the washout of sediment through log gaps. Filter fabric shall extend from the bottom of footer log to the finished grade elevation and shall be placed the entire length of the structure. Header and footer logs shall be tied in securely to the bank in such a way that eliminates the possibility of water diverting around them. Structures shall be built to the approval of the Designer. The Designer may adjust the number and placement of structures in the field.

Basis of Payment This payment shall be considered full compensation for all labor, equipment, hauling, placing, handling, sorting, fitting, materials, and incidentals necessary to construct the Log Vane. Trees to be used for the vane shall be provided by the Forest Service.

Payment will be made under:

Equipment & Labor………………………………………………………………………………..….…..HOURS Materials:

Non woven geotextile fabric…………………………………..……….……………....LINEAR FOOT

Toe-wood/Sod mat (bankfull bench)

This structure serves to protect a length of stream bank by biulding a new bank with a bankfull area where one did not exist before due to unstable conditions (See Toe-wood/Sod mat detail below). The structure creates a large undercut bank providing an abundance of aquatic cover type habitat.

Materials Trees and brush to be used for the structure shall be provided by the Forest Service from near the site. Shrubs and willow shall be provided by the Forest Service from near the site. Excavated soil shall be hauled off the site and dumped within 5 miles by the contractor. Seed, mulch, coir matting, and riparian plantings (live stakes, potted material, etc.) shall be provided and installed by the contractor.

Installation The channel shall be excavated to build a bench on the channel bottom on the outside of the meander bend. Its elevation shall be well below determined low water elevation. A deep pool shall be constructed where the new thalweg will be located, and excavated material shall be used to build the point bar and back fill the structure. Footer logs laying parrallel to the stream channel shall be placed on the bench, then the toe-wood on top of that. Toe-wood shall consist of a mixture of sizes, but include several large tree stems with root wads attached. Stems shall be pushed into the bank were possible. Trees, brush, and limbs shall all be used to fill this area with woody debris, and be placed up to the low flow elevation. Bundles of live stakes, e.g. willow, shall be placed on top of the woody debris and alluvial backfill shall be placed on the structure (amount determined by Designer). Shrubs, excavated from nearby, shall be placed on top of the toe-wood up to the bankfull elevation. This shrub mat will replace the “sod mat”. From the bankfull elevation the verticle slope shall be excavated to the 2:1 slope (run to rise). Excavated soil material shall be scattered on the adjacent terrace. All slopes shall have seed, mulch, and coir matting installed. Riparian plantings shall be installed on the slope and during the plant dormant season, live stakes shall be installed in the bench and bank.

This payment shall be considered full compensation for all labor, equipment, hauling, placing, handling, sorting, fitting, materials, and incidentals necessary to construct the bankfull bench. Trees to be used for the structure shall be provided by the Forest Service.

Payment will be made under:

Equipment & Labor………………………………………………………………………………..….…..HOURS Materials:

EROSION CONTROL SPECIFICATIONS

Seed (Native)

Description Seeding shall occur within 24 hours of ground disturbing activities. Seed shall be applied by hand or with a cyclone seeder and on steep slopes be immediately covered with leaf litter , raked in from the surrounding area. On stream banks, biodegradable matting/blanket shall be placed to keep seed and soil in place. Below are native grass species to be sown and their seeding density of pure live seed.

Community Type: Riparian

Materials All materials shall meet the approval of the Designer.

Basis of Payment Payment for installation of seed and mulch will be paid for as outlined. This payment shall be considered full compensation for all labor, equipment, furnishing materials, hauling, rehandling, sorting, materials, and incidentals necessary to seed and mulch.

Payment will be made under:

Seed ………………………..……………………………………………………………….…………………..ACRE

Matting

Description/Installation Coir fiber mat 700 shall be used on upper and lower stream banks (above and below the bankfull elevation). The matting shall be fastened in place using hardwood stakes. During the following plant dormant season, live stakes shall be planted in the matting from water’s edge to just above bankfull. Species include silky dogwood (Cornus ammonum), black willow (Salix nigra), silky willow (Salix sericea), ninebark (Physocarpus opulifolius) and common elderberry (Sambucus canadensis) from a local source.

Provide stakes made of hardwood to anchor the matting. Stakes shall be installed to no less than 1 foot deep for use on side slopes and along the top edge of matting.

Place the matting upon final grading, following seed and mulch application. Provide a smooth soil surface free from stones, clods, or debris which will prevent the contact of the matting with the soil. Unroll the matting on the contour, starting at the bottom of the slope and apply without stretching such that it will lie smoothly but loosely on the soil surface. Bury the top end of each piece of matting in a narrow trench at least 6 in. (150 mm) deep and tamp firmly after staking with evenly spaced stakes. Stake the matting according to the manufactures recommended pattern for specific product and slope. Where one roll of matting ends and a second roll begins, install matting end-over-end with approximately 6 inches of overlap. Stake through overlapped area. Install stakes across the matting at ends, junctions, and trenches approximately 1.3 feet apart.

Materials All materials shall meet the approval of the Designer and include Coir fiber mat 700, hardwood stakes, and live stakes (see “Planting” Specs).

Basis of Payment Payment for installation of matting will be paid for as outlined. This payment shall be considered full compensation for all labor, equipment, furnishing materials, hauling, stockpiling, rehandling, sorting, fitting, materials, and incidentals necessary to install matting.

Payment will be made under:

Matting …………..……………………………………………………………………….………..LINEAR FOOT

Plantings

Description Plantings shall be specified in each contract as to type e.g., container, bare root, and live staking. Plantings from containers shall be from one gallon containers and can be planted throughout the year. Live staking and bare root planting shall occur during plant dormancy. Bare root seedlings shall be 6 to 12 inches tall. Below is a list of woody vegetation species to be planted on stream banks and floodplains.

Container & Bare Root Species:

Itea virginica

Live Stake Species:

Materials All materials shall meet the approval of the Designer.

Basis of Payment Payment for installation of plantings will be paid for as outlined. This payment shall be considered full compensation for all labor, equipment, furnishing materials, hauling, rehandling, sorting, materials, and incidentals necessary to plant.

Payment will be made under:

Plantings…..………………………………………………………………………………..…………………EACH

Fabric Lined Diversion Channel

A fabric lined temporary diversion channel is used to divert normal stream flow and small storm events around the work area without the use of pumping operations. It is appropriote when adequate space and slopes exist adjacent to the work area. The temporary diversion channel is typically constructed adjacent to the work area and is lined with a poly-fabric to minimize the potential for erosion within the temporary diversion channel.

Materials All materials shall meet the approval of the Designer.

Installation Step 1 – Install sediment controls.

Step 2 – Excavate the diversion channel without disturbing the existing channel.

Step 3 – Place poly-fabric liner in diversion channel with a minimum of 2 feet of material overlapping the channel banks. Secure the overlapped material using at least 1 foot of fill material.

Step 4 – Connect the downstream diversion channel into the downstream existing channel and secure the poly-fabric liner at the connection.

Step 5 – Connect the upstream diversion channel into the upstream existing channel and secure the poly fabric liner at the connection.

Step 6 – Construct an impervious dike in the existing channel at the upstream side to divert the flow into the diversion channel.

Step 7 – Construct an impervious dike in the existing channel at the downstream side to isolate the work area.

Step 8 – Upon completion of the culvert construction, pump water from behind downstream dike into a sediment bag placed on the energy disipation rip rap, remove the impervious dikes and divert the channel back into the stream.

Step 9 – Remove the poly-fabric liner and fill in the diversion channel.

Step 10 – Establish vegetation on fill section and all other bare areas.

Maintenance Check the poly-fabric liner for stability during normal flow.

Check the liner for stability after each rainfall event.

Do not allow earthen material to contact the water body.

Payment for installation of lined diversion channel will be paid for as outlined. This payment shall be considered full compensation for all labor, equipment, furnishing materials, hauling, rehandling, sorting, materials, and incidentals necessary to plant.

Payment will be made under:

Equipment & Labor..………………………………………………………………………..………………HOURS Materials:

Temporary Gravel Construction Entrance

Description Access roads on the project site shall be limited to the designated routes and locations that are depicted on the construction plans. Damage to any existing road or vegetation shall be repaired to a condition that is at least as good as the condition before start of construction, as directed by Designer. Soil material excavated from the project site shall be used as fill material to construct the entrance, a length of 50 feet and a width of 20 feet minimum. On the final grade surface filter fabric shall be laid on the running surface then covered by a minimum of 8 inches of Number 57 stone. Slopes shall be constructed to a stable angle, shaped and dressed to the satisfaction of the Designer. Following project completion, the soil shall be scarified, and the site stabilized using erosion control measures.

Basis of Payment Payment for installation of access routes will be paid for as outlined. This payment shall be considered full compensation for all labor, equipment, furnishing materials, hauling, weighing, stockpiling, rehandling, sorting, fitting, materials, and incidentals necessary to construct the drivable access route.

Payment will be made under:

Equipment & Labor………………………….………………………………………………………..….…..HOURS Gravel……………………………………………………………………………………………………………..TON

CONSTRUCTION PLANS, DRAWINGS, & MAP

ITEM 1 – Tributary to Hiwassee River Stream Restoration Project

Project Description: This project, located on the Tusquitee Ranger District, Nantahala National Forest in Cherokee County, North Carolina, proposes to construct a stable stream ecosystem using natural channel design techniques.

The 1,307 feet reach of stream is on the 100-year floodplain of the Hiwassee River at the Tusquitee Ranger Station property in Murphy, NC (Figure 1). This area has been impacted by Native American villages, farming, flooding, and development. Current impacts to the stream include increased peak flows from compacted areas in the watershed, mowing of stream bank vegetation, an entrenched stream channel without adequate floodplain access, lateral stream channel instability, and non-native invasive plants (Figure 2 & 3). As a result, sections of stream bank within the reach are unstable; aquatic habitat diversity is lacking; and streamside and alluvial forests are degraded.

Project Goals & Objectives: The goals and objectives of this project are to establish a new channel dimension, pattern, and profile based on reference reach information, thus restoring natural form and function. The project will improve the health of the stream ecosystem by improving channel stability and habitat quality, along with improving riparian and streamside vegetation conditions. The desired condition is to have high quality riparian areas and aquatic habitat features that maintain hydrologic function, enhance stream stability, and minimize erosion.

Construction Schedule:

Construction activities shall occur during a four week period. See Figure 4 for stream Section locations and Figures 5-7 for plan view of proposed action. Following is the Construction Schedule for the project:

Section A:

· Reconstruct the channel and enhance existing floodplain formation at the existing channel elevation within the confined “gully”. Construct a stable stream channel using natural channel design techniques - a Rosgen “B” stream type as guided by reference reach information (Table 1).

· Disturbance could occur within 50 feet either side of the existing channel. Soil disturbance would include excavation of the gully banks to a stable angle, and construction within the channel of floodplains and several instream structures made from trees and boulders. Soil excavation would likely exceed fill material; therefore excess soil would be removed from the site by the contractor. Additional disturbance would include the movement of equipment over the area.

Section B:

· The current location of this channel would remain and structures would be used to stabilize the channel and create a Rosgen “B” stream type.

· Retrofit the FSR 319 crossing with a boulder structure at the outlet to promote back water into the pipe for aquatic organism passage.

· Disturbance could occur within 50 feet of the left downstream side of the existing channel. Type of disturbance would include excavation of steep stream banks to a stable slope, construction of floodplains, and construction of structures, and the movement of equipment over the area.

General:

All disturbed area would be seeded with native grass seed and mulched, and stream banks would be seeded and matted with erosion control matting and vegetation transplants, and planted with native riparian type vegetation.

Figure 1. Project vicinity map for the Tributary to the Hiwassee River Stream Restoration project..

Figure 2. Photos of site in Section A.

Figure 3. Surveyed plan view of existing condition in entire reach.

Figure 4. Sections of work for construction reference.

Figure 5. Plan view of proposed action, Segment A, upper reach.

Figure 6. Plan view of proposed action, Segment B, tributary lower reach.

Figure 7. Plan view of proposed action, Segment B, lower reach.

Table 1. Reference reach data and proposed channel dimensions, pattern, and profile.

1 refer to reference reach plots

2 based on reference reach and observed/measured values from the project stream

Examples of in-stream structures

Typical of a Toe-wood bankfull bench structure (concept originating from Wildland Hydrology, 2012).

Example of a stabilized meander bend and completed toe-wood bankfull bench on Boone Fork, Grandfather RD, constructed October 2012.

Photo A – Before Construction

Photo B – After Construction

Tributary to Hiwassee River Stream Enhancement Project 2014 Page 22

Example of a stabilized meander bend and completed toe-wood bankfull bench structure on Back Creek, Grandfather RD, constructed May 2012.

Photo A – Before Construction

Photo B – After Construction

Typical of a log vane.

Example of Log Vane structures.

Back Creek, Grandfather Ranger District, constructed May 2012.

Boone Fork, Grandfather Ranger District, constructed October 2012.

North Fork Mills River, Pisgah Ranger District, constructed September 2009.

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Microsoft_PowerPoint_Slide1.sldx

Constructed pool bankfull elevation toe of bank bankfull elevation

20o angle

1/3 channel bankfull width toe of bank

CROSS VANE DETAIL

PLAN VIEW

HEADER ROCK

Flow Direction

High Flow

MATERIAL FROM POOL USED TO CONSTRUCT INNER BERM

MATERIAL FROM POOL USED TO CONSTRUCT INNER BERM

Brady Dodd

NFNC Hydro

1/3 channel bankfull width

FOOTER ROCK

20o angle

High Flow image1.jpeg image2.jpeg image3.jpeg image4.jpeg image4.jpg image5.emf image6.png image7.png image8.jpeg image9.jpeg image10.jpeg image11.emf image12.jpeg image13.png image14.png image15.png image16.jpg image17.jpeg image18.jpeg image19.jpeg image20.jpeg image21.jpeg image22.jpeg image23.jpeg image1.emf