Preliminary Geotechnical/Hazard Assessment for Proposed Subdivision 102 Atkins Road

Preliminary Geotechnical/Hazard Assessment for Proposed Subdivision

102 Atkins Road – View Royal, BC

As requested, we have completed a preliminary assessment of the referenced site, to identify any geotechnical/hazard issues that could adversely impact the proposed development. This letter summarizes our observations and presents our preliminary comments, but does not provide detailed recommendations regarding issues such as blasting, rock scaling, engineered fill placement, etc. Although none of these issues are expected to present any unique challenges, the details can only be provided once more detailed designs, including grading plans, etc., are developed. We would be pleased to work with your civil engineer on these matters at a later date, if required. Our work has been undertaken in accordance with, and is subject to, the attached Terms of Engagement.

Generally, the site is a triangular parcel bounded to the east by Chilco Road, to the northwest by the E & N Railway, and to the southeast by the Galloping Goose Regional Trail, with Atkins Road beyond. There is an existing house and garage in the northeast part of the lot, accessed by a driveway that ascends from Chilco Road, and an old concrete foundation is located further to the southwest. Ground cover ranges from grass in the vicinity of the noted buildings to bare rock northeast of the house and mixed trees and brush in the southwest part of the site. There is an elevation difference of about 7 m between Chilco Road and the crest of a rock knoll northeast of the existing house, and beyond the house the ground slopes gradually down to the southwest. Much of the northwestern property line roughly coincides with the toe of the railway embankment (the railway is about 4 -5 m above the level of the ground surface in front of the house), and it is possible that associated fill encroaches onto the subject property.

We understand that the proposed development would consist generally of 8 to 9 single-family residences, accessed by a new road to be constructed along the southwest property line, off Chilco Road. The narrow southwestern part of the lot, as well as the northern-most portion, would not be developed. Key development issues are likely to include rock excavation (blasting) in the northeastern part of the site, possible fill placement in the southwest portion (depending upon design grades), and possible drainage issues. Retaining walls could be required in some areas, particularly if fill associated with the railway encroaches into any of the building sites. Foundation bearing conditions will likely be good across most of the site, but softer soils could be encountered in the southwest. None of these conditions are considered unique or unusually challenging.

Our assessment is that the proposed building sites will generally be safe and free from natural geohazards, but specific measures could be required to protect some of the buildings from rockfall from excavated rock faces. Such measures could include scaling, construction of rockfall containment structures, or even localized rock bolting, but this can only be determined once the rock faces can be examined following blasting. In this regard, and provided that all natural and excavated rock faces near the building sites are assessed by a qualified geotechnical professional at the time of construction, it is our assessment that the land can be safely used for the use intended, that being an 8 to 9 lot residential subdivision. This is pursuant to and in accordance with Section 56 of the Community Charter. The detailed geotechnical assessment should take into account the effect of a seismic event with a 2% probability of exceedence in 50 years where such has the potential to impact a residence. The stability of the railway embankment should also be considered for any residences located close to it.

We trust that the preceding is suitable for your purposes at present, however if you have any questions with respect to the above, please contact us.

Yours very truly, Ryzuk Geotechnical

Bruce R. Dagg, P.Eng. Geotechnical Engineer

Attachment – Terms of Engagement