SECTION_J_MechanizedEquipmentOperationsInRCAs.docx

Mechanized Equipment Operations in Riparian Conservation Areas (RCAs)

Operations in Perennial and Intermittent Stream RCAs:

The RCA is divided into three zones to provide a wide, graduated buffer so that riparian conservation objectives and management objectives can be achieved. The zone nearest the stream is an exclusion zone that prohibits mechanized equipment. The next zone is a transition zone that allows light use. The third zone is an outer zone that allows additional use as distances increase from the stream. See Figure 1 for a diagram of the three zones. The objective of the exclusion and transition zones is to retain a high percentage of ground cover and prevent detrimental soil compaction and displacement. The intent of the outer zone is to allow activity to increase from light use in the transition zone to standard operations beyond the RCA.

15’ 50’ 100’ Exclusion Zone-Skid Transition Zone-Skid and Mech Outer Zone

1. Limitations: 90% or more of equipment footprints have ruts no deeper than 4” and tracked area retains at least 90% cover of organic material

1. Limitations: tracked area must retain at least 50% organic cover evenly distributed

PERENNIAL STREAM RCA

INTERMITTENT STREAM RCA

Mech. Harvest & Shred Equip.

Skidding Equip.

NO

NO

NO

Yes (1) Yes (2) Yes (2) Gradient to Standard Ops Gradient to Standard Ops 300’ 150’ Transition Zone-Mech

Exclusion Zone-Mech

Figure 1: Equipment operations in perennial and intermittent stream RCAs.

Exclusion Zone

0. The exclusion zone starts at:

0. The edge of the active channel where slopes rise uniformly from the stream, or at the outer edge of the following features, whichever is furthest from the stream.

0. The first slope-break adjacent to the stream (e.g., streambank, outer gorge)

0. Flat or nearly flat ground adjacent to the channel (e.g., floodplain or terrace)

0. Obligate riparian shrub and/or tree communities associated with any of the above.

For example, if the edge of the active channel is 2 feet from the water’s edge, the first slope break is 5 feet from the water’s edge, the floodplain is 15 feet from the water’s edge, and the obligate riparian vegetation extends 25 feet from the water’s edge, then the exclusion zone would start at the edge of the obligate riparian vegetation, since it is furthest from the stream. In Figure 1 above, this start of the exclusion zone is labeled as 0 feet.

· Skidding equipment (e.g., rubber-tired skidders and track-laying tractors) may not come within 50 feet of the start of the exclusion zone, and mechanical harvesting and shredding equipment (e.g., feller bunchers and masticators) may not come within 15 feet from the start of the exclusion zone. In the example described above, where the obligate riparian vegetation extends 25 feet from the water’s edge, mechanical harvesting equipment would remain 40 feet from the water’s edge (25 feet to the start of exclusion zone + 15 foot exclusion zone) and skidding equipment would remain 75 feet from the water’s edge (25 feet to the start of exclusion zone + 50 foot exclusion zone).

· Operation created debris would be removed from stream channels. No damage to streambanks from equipment would be allowed. All vegetation that is maintaining streambank stability would be retained. All obligate riparian shrubs and trees (i.e., willows, alders) would be retained.

Transition Zone

0. The transition zone for skidding equipment is 50 feet wide and starts at the end of the exclusion zone (labeled as 50 to 100 feet in Figure 2).

· Where skidding equipment is operating, retain a minimum of 50% evenly distributed ground cover in the tracked area. Existing skid trails should be used except where unacceptable impact would result. Do not create new skid trails within 100 feet of a stream. The number of perennial and intermittent stream crossings should not exceed an average of 2 per mile.

· The transition zone for mechanized harvesting and shredding equipment is 85 feet wide and starts at the end of the exclusion zone (labeled as 15 to 100 feet in Figure 2).

· For the first 35 feet of the transition zone for mechanized harvesting equipment (labeled as 15 to 50 feet in Figure 1), operations may only be allowed when continuous ground cover can be retained in 90% of the tracked area, and where 90% of the total tracked area is rutted less than 4” deep. For the last 50 feet of the transition zone for mechanized harvesting equipment (labeled as 50 to 100 feet in Figure 2), retain a minimum of 50% evenly distributed ground cover in the tracked area.

Operations in Ephemeral Stream RCAs:

Ephemeral streams have running water only during or shortly after rainfall and/or snowmelt, and show evidence of annual channel scour.

Exclusion Zone

0. The exclusion zone begins at the edge of the active channel where slopes rise uniformly or at the edge of the streambank, whichever is furthest from the stream.

0. The exclusion zone for skidding equipment near ephemeral streams is 25 feet from the start of the exclusion zone. The exclusion zone for mechanical harvesters and shredding equipment is 15 feet from the start of the exclusion zone.

Transition Zone

0. The transition zone for skidding equipment is 25 feet wide and starts at the end of the exclusion zone.

0. The transition zone for mechanical harvesting equipment is 35 feet wide and starts at the end of the exclusion zone

0. Within the transition zone for both skidding and mechanical harvesting equipment, retain a minimum of 50% evenly distributed soil cover in project-created tire or tracked vehicle footprints. The number of ephemeral stream crossings should not exceed an average of 3 per mile.