MEMO 1065318 Vista Del Mar Vegetation Edmonds��
N
Main Office
17311 — 135" Ave NE, A-500
Woodinville, WA 98072
(425) 486-1669 • FAX (425) 481-2510
DATE: February 1, 2019
NELSON GEOTECHNICAL
ASSOCIATES, INC.
GEOTECHNICAL ENGINEERS & GEOLOGISTS
MEMORANDUM
TO: Mr. Garth Hitchens
c/o Robin Kearsley — Kearsley Homes
FROM: Khaled M. Shawish, PE
Alex B. Rinaldi, GIT
RE: Bluff Setback Vegetation Management
Hitchens Residence Development
Edmonds, Washington
NGA File No. 1065318
Engineering -Geology Branch
5526 Industry Lane, #2
East Wenatchee, WA 98802
(509) 665-7696 • FAX (509) 665-7692
This memorandum presents our recommendations for slope protection and vegetation management within
the gently sloping setback areas to the west of the proposed residence.
Erosion Control/Vegetation Management
Areas of exposed soils below and to the west of the residence should be covered with erosion control
matting, and then planted with deep -rooting plants. We recommend that the exposed soil be covered with
heavy duty erosion control matting such as Tensar C350 Turf Reinforcement Mat, or equivalent. The
erosion control matting should be staked to the surface at a minimum of 5 feet on center using 2- to 3-foot
long metal stakes with a "T" welded to the end. After the matting is placed, we recommended that deep-
rooted vegetation be planted and grass seed be placed to re-establish vegetation growth. For shrubs, we
recommend a mixture of 25% each of the following species: Snowberry (Symphoricarpos albus), Nootka
rose (Rosa nutkana), Ocean Spray (Holodiscus discolor), and Oregon -grape (Mahonia nervosa). New
vegetation should be maintained until established.
No material of any kind should be placed on the slope or be allowed to reach the slope. Any future
proposed activities on or near the slope should be the subject of a specific geotechnical evaluation. Under
no circumstances should water be allowed to concentrate on the slope either during construction or on a
permanent basis after construction has been completed.
Bluff Setback Vegetation Management Memorandum
Hitchens Residence Development
Edmonds, Washington
NGA Project No. 1065318
February 1, 2019
Page 2
Future yard waste, grass clippings, or any other waste material or household trash should never be cast
over the slope. Such activity could lead to slope instability. Additionally, drainpipes associated with the
new residence, should all be tightlined to an approved stormwater management system.
Closure
We recommend that we be retained to review final plans and monitor repairs during construction. We
should also work with your other team members and contractors on finalizing project plans.
We trust that this memorandum should satisfy your needs at this time. Please do not hesitate to contact us
should you require anything further.
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NELSON GEOTECHNICAL ASSOCIATES, INC.