Or. Admin. R. 141-089-0730

Current through Register Vol. 63, No. 8, August 1, 2024

Section 141-089-0730 - Waterway Bank stabilization - Authorized Activities

(1) Bio-Engineering. This activity includes placement of woody vegetation, vegetated geogrids, biodegradable logs, straw bales or straw logs used for bank protection, bank reshaping, terracing and erosion control.

(2) Bank Terracing. This activity includes bank terracing and sloping to facilitate establishment of woody vegetation. The project must meet the following criteria:

(a) The slope must not be steeper than 3:1 (H/V) ratio;

(b) Bank treatments must be replanted with native woody vegetation; and

(c) If fabric is necessary, no petroleum-based fabric is allowed.

(3) Placement of Large Wood. Trees or root wads may be used. The project must meet the following criteria:

(a) Trees must have a trunk diameter greater than or equal to 12 inches;

(b) The basal ends must be oriented upstream;

(c) If fastening is necessary, only smooth, single-string wire, degradable rope or pinning may be used. Braided wire cable is not allowed; and

(d) If anchoring is necessary, only rock ballast, untreated wood posts, stabilizing wood or key pieces of wood may be used as anchors.

(4) Engineered Log Jams. Log jams may be placed in order to stabilize the bank for woody vegetation establishment. The project must meet the following criteria:

(a) The length of key pieces of wood with trimmed rootwads must be one and one-half times the bankfull width or a minimum of 25 feet in length when bankfull width exceeds 15 feet. The length of key pieces of wood with trimmed rootwads must be the twice the bankfull width or a minimum of 30 feet in length when bankfull width exceeds 15 feet;

(b) Large wood must be intact, hard and undecayed to partially decayed hardwoods or conifers;

(c) The log jam must not occupy more than 20 percent of the bankfull width;

(d) If fastening is necessary, only smooth, single-string wire, pinning or degradable rope may be used. Braided wire cable is not allowed; and

(e) If anchoring is necessary, only rock ballast, untreated posts, stabilizing wood or key pieces of wood may be used as anchors.

(5) Log Toe Placement. The project must meet the following criteria:

(a) Log toes must not extend more than one foot above the elevation of the water at base flow; and

(b) Logs must be large enough to withstand the hydraulic energy in the stream and be anchored securely to the bank by burial.

(6) Porous Weir. This activity includes the construction of a self-sustaining, low profile, structure including but not limited to cross vanes and artificial riffles. A porous weir delays but does not store water. It is used to redirect flow toward the center of the channel, provide energy dissipation and promote increased sedimentation along banks while allowing fish passage through a porous design. The project must meet the following criteria:

(a) Porous weirs must be placed so scour pools occur in areas where pools would naturally form in a pool and riffle complex;

(b) Porous weirs must not result in culvert inlet or outlet scour;

(c) Porous weirs must be sized appropriately for the system so as not to require annual maintenance;

(d) Porous weirs must be constructed of materials that mimic natural substrate found within the system;

(e) The structure must not exceed 100 cubic yards and 40% of the channel cross-section width; and

(f) The activity is limited to 100 cubic yards for every one-half mile of waterway, unless otherwise approved by the Department.

Or. Admin. R. 141-089-0730

DSL 2-2011, f. & cert. ef. 3-1-11; DSL 15-2018, minor correction filed 01/03/2018, effective 1/3/2018; DSL 2-2024, amend filed 05/31/2024, effective 7/1/2024

Statutory/Other Authority: ORS 196.600 - 196.692 & 196.795 - 196.990

Statutes/Other Implemented: ORS 196.600 - 196.692 & 196.795 - 196.990