**NATURAL RESOURCES CONSERVATION SERVICE**

**CONSERVATION PRACTICE CONSTRUCTION SPECIFICATION**

**STREAMBANK AND SHORELINE PROTECTION - WIRE BOUND RIPRAP**

**CODE 580W**

1.  **SCOPE**

> The work shall consist of the construction of wire bound rock riprap
> including bedding. This specification does not apply to gabions.

2.  **SITE PREPARATION**

> Site preparation (mobilization and demobilization, clearing and
> grubbing, structure removal, pollution control, and water for
> construction) shall be in accordance with Construction Specification
> 587.

3.  **MATERIALS**

> The wire mesh shall be galvanized steel wire (12 gage, minimum, with a
> Class 3 zinc coating), fabricated into double-twist mesh of
> non-raveling construction or welded wire mesh. The mesh openings shall
> be uniform in size and shape. Woven wire mesh shall be approximately
> 2½ inches by 3¼ inches in size and welded wire mesh shall be
> approximately 1½ inches by 3 inches in size, unless otherwise shown on
> the drawings.
>
> Tie wire and lacing wire shall be 12-gage galvanized steel wire.
>
> Rock shall be hard and durable and be approved by the engineer prior
> to placing. The minimum rock size shall be 4 inches, the maximum rock
> size shall be 6 inches for a riprap thickness of 12 inches or less,
> and the maximum rock size shall be 9 inches for a riprap thickness
> greater than 12 inches.
>
> Bedding shall be uniformly graded gravel ranging from ¼ inch to 2
> inches.
>
> Stakes shall be steel angles at least 2 x 2 x ¼ (inches) in dimension.

4.  **FOUNDATION WORK**

> Foundation work (diverting surface water, dewatering the construction
> site, dewatering borrow areas, and foundation preparation) shall be in
> accordance with Construction Specification 587.
>
> Bedding and/or riprap shall not be placed until the foundation
> preparation is completed and the subgrade surfaces have been inspected
> and approved by the engineer.

5.  **EARTHWORK**

> Earthwork (common excavation and earthfill) shall be in accordance
> with Construction Specification 587.

6.  **BEDDING**

> The bedding material shall be spread uniformly on the prepared
> foundation surface to the depth specified and shall be free of mounds,
> dips, or windrows. Compacting of bedding will not be required. The
> surface of the bedding shall be approved by the engineer prior to the
> placement of the rock riprap.

7.  **PLACEMENT OF RIPRAP**

> The rock shall be placed on the surfaces and to the depths specified.
> The riprap shall be constructed to the full course thickness in one
> operation and in such a manner as to avoid serious displacement of the
> underlying materials. The rock shall be delivered and placed in a
> manner that will ensure that the riprap in place shall be reasonably
> homogeneous with the larger rocks uniformly disturbed and firmly in
> contact one to another with the smaller rocks and spalls filling the
> voids between the larger rocks. Riprap shall be placed in a manner to
> prevent damage to structures. Hand placing will be required to the
> extent necessary to prevent damage to the permanent works.

8.  **PLACEMENT OF WIRE**

> The woven wire shall be placed on the bedding, then rock placed
> thereon, and the outer cage of wire placed over the rock. The lower
> cage of wire shall be tied to the upper edge by interconnecting ties
> on a two-foot spacing grid pattern. Woven wire shall overlap one-foot
> and spliced with ties on 6-inch spacings, except selvaged edges will
> not require overlap. Use a loop with three full twists for all ties.
> The finished job shall be a wire-bound riprap where the rock is fully
> enclosed by woven wire including the footing, ends, and sides.
>
> Steel anchors shall be of the length as shown on the drawings and
> shall be driven into the riprap on five-foot centers in both
> directions.

9.  **MEASUREMENT**

> The volume of the riprap and the volume of bedding will be separately
> measured within the specified limits as shown on the drawings and
> computed to the nearest cubic yard by the method of average
> cross-sectional end areas.
>
> Project Name:
>
> Date:

10. **ITEMS OF WORK AND CONSTRUCTION DETAILS**

> Items of work to be prepared in conformance with this specification
> and the construction details are: