Attachment 5: Riparian Areas Protection Regulation - Assessment Report (Form 1, Sections 4-8)

Riparian Areas Protection Regulation - Qualified Environmental Professional - Assessment Report

Section 4. Measures to Protect and Maintain the SPEA

1. Danger Trees

No danger trees were identified during the site visit. The arborist did not identify any danger trees during the preparation of the Tree Management Plan for Sub-division and Site Servicing (Gye and Associates Draft Tree Plan dated January 11, 2022) (Appendix C – Tree Management Plan).

Following site servicing, and prior to construction, a danger tree assessor or arborist must review the retained trees adjacent to the proposed construction footprint to evaluate if any risk from danger trees exists. All trees within the proposed SPEA must be retained unless determined by an arborist to be a hazard tree (danger tree). If any hazard trees are identified within the SPEA, the trees should be cut as wildlife trees, if possible. Any danger trees removed within the SPEA must be replaced with native trees species, and the number of replacement trees must be determined based on the 1996 B.C. Ministry of Environment Tree Replacement Criteria.

Some (off-site) boulevard trees are noted for removal along and within the identified SPEA of the ditch along Atkins Road as part of site servicing. These trees are generally identified as being in poor to fair health and in poor structural condition. The arborist recommends removal of these poor condition trees during site servicing and replacement with trees better suited for the conditions. It is recommended that all trees within a SPEA are retained but given the limited nature of the drainage ditch and the lack of LWD requirements for ditches, this proposal is acceptable provided the tree replacement criteria is followed and replanting is focused along the ditch SPEA in compliance with any requirements of a approved Tree Permit under the View Royal Tree Protection Bylaw (No 695), 2009.

I, Tim Adam, hereby certify that: i) I am a qualified environmental professional, as defined in the Riparian Areas Protection Regulation made under the Riparian Areas Protection Act; j) I am qualified to carry out this part of the assessment of the development proposal made by the developer David McAllister; k) I have carried out an assessment of the development proposal and my assessment is set out in this Assessment Report; and in carrying out my assessment of the development proposal, I have followed the assessment methods set out in the Minister’s technical manual to the Riparian Areas Protection Regulation.

2. Windthrow

The trees present on the site and adjacent to the site have been reviewed as part of the Tree Management Plan for Sub-division and Site Servicing (Appendix C – Tree management plan) but specific recommendation regarding wind firmness are not included.

Some trees noted for removal may be growing in co-dominance with retained trees and their removal may compromise their wind firmness. Trees within the ravine exhibit signs of soil creep, pistol butting and fallen trees are present within the ravine. Removal of existing mature trees for site servicing and building construction may impact the wind firmness of the retained trees (onsite, offsite and within the SPEA).

It is recommended that a qualified arborist or registered professional forester address the risk of windthrow in association with the proposed tree clearing required for the development (site servicing and construction). Stable falling boundaries and any tree treatments (e.g. spiral pruning, crown reduction) to improve wind firmness of new edge trees must be established and completed outside the SPEA.

I, Tim Adam, hereby certify that: a. I am a qualified environmental professional, as defined in the Riparian Areas Protection Regulation made under the Riparian Areas Protection Act; b. I am qualified to carry out this part of the assessment of the development proposal made by the developer David McAllister; c. I have carried out an assessment of the development proposal and my assessment is set out in this Assessment Report; and in carrying out my assessment of the development proposal, I have followed the assessment methods set out in the Minister’s technical manual to the Riparian Areas Protection Regulation.

3. Slope Stability

A slope stability assessment was completed for the proposed subdivision by Ryzuk Geotechnical Engineering and Material Testing dated March 5, 2019 (Appendix B – Geotechnical Report) and a further geotechnical field review and site instruction memo was completed, dated November 24, 2020 (Appendix B – Geotechnical Report). The geotechnical report was prepared assuming a three-lot subdivision based on an earlier plan for the property. The proposed two-lot design does not include any changes which could increase the potential risk to slope stability so an update to the geotechnical report was not completed. The current Lot 1 includes the area of the original Lot 1 and Lot 2, and the current Lot 2 is a narrower version of the original Lot 3.

A geotechnical setback line which includes the “limit of disturbance” to protect trees (Appendix C – Tree Management Plan) and the calculated SPEA for Millstream as determined by this report into its revised plan for unloading the ravine top of bank. The original plan proposed unloading Lot 1 and 3 (now Lot 1 lot 2) by 3.5 m to 2.0 m bellow existing lot grades. The proposed design requires unloading only Lot 2. The “limit of disturbance” line is intended as the boundary beyond which no ground disturbance, grading or soil removal can occur as to protect the Millstream SPEA and the protected trees located within the SPEA.

A geotechnical setback of 6.0 m for all structures is then applied for the new unloaded ravine top of bank in Lot 1 and Lot 3 (now Lot 1 and Lot 2) and the existing ravine top of bank in areas which are not to be unloaded (Figure 3). This setback is based on conventional shallow spread footings. The geotechnical report includes a geotechnical setback line along the small side ravine on the north side of Lot 1 along the “limit of disturbance” line to protect the off site trees and the steep slopes associated with this area (Figure 3).

Recommendations from the Ryzuk Geotechnical Engineering and Material Testing dated March 5, 2019 include:

• Minimal disturbance of vegetation should occur within the area between the slope crest and the proposed residences.
• Areas subject to excavation/unloading along the slope crest should be excavated with care and re-vegetated as soon as possible.
• Landscaping features should be constructed such that surface flows are not concentrated to discharge at the slope crest. Alternatively, collected water could be conveyed downslope via secured solid pipe network and discharged onto non-erodible soils

Recommendations from the geotechnical field review and site instruction memo, dated November 24, 2020 include:

• Excavation works associated with the slope unloading and site preparations should be carried out with care in accordance with recommendations from a qualified professional.
• Excavation cut slopes should be prepared in a stable configuration to ensure stability over the short to medium term in the event the lots are not developed immediately (e.g. 1:1 slopes).

I, Tim Adam, hereby certify that: a. I am a qualified environmental professional, as defined in the Riparian Areas Protection Regulation made under the Riparian Areas Protection Act; b. I am qualified to carry out this part of the assessment of the development proposal made by the developer David McAllister; c. I have carried out an assessment of the development proposal and my assessment is set out in this Assessment Report; and in carrying out my assessment of the development proposal, I have followed the assessment methods set out in the Minister’s technical manual to the Riparian Areas Protection Regulation.

4. Protection of Trees

General recommendations on the protection of trees is provided in the Gye and Associates Tree Management Plan for Sub-division and Site Servicing dated January 11, 2022 (Appendix A). The Tree Management Plan also includes markup of all anticipated on-site tree removals for lot buildout. Arborist review and support will be required to allow site servicing and house construction to avoid impacts to retained trees, trees within the SPEA and off-site trees (boulevard and adjacent off-site trees) including any restoration planting. The ten general tree protection recommendations provided in the January 11, 2022 report are:

1. Pre-construction meeting: Before demolition or site-servicing begins, the contractor shall meet with the arborist to review the placement of fencing and other tree protection measures within this plan. a) The Project Arborist shall clearly mark the boundaries of all areas to be fenced and protected. b) Access routes and areas for trade parking and materials storage will be identified with the contractor.
2. Tree Fencing: a) Tree protection fencing shall be installed to the Township of View Royal standards at the locations indicated on this drawing prior to demolition or site servicing permits being issued (see fencing detail on plan). b) Tree protection fencing, and armouring shall be maintained in good condition throughout the duration of the project. c) Requests to temporarily remove or move tree fencing must be reviewed by the project arborist for approval.
3. Tree Management Plan posting: a) A full-sized weather-proof copy of this tree plan shall be posted in plain sight in the site office. b) The general contractor shall ensure that all relevant sub-trades are familiar with the drawing and tree protection measures.
4. Site servicing and excavations: The project arborist shall be present to oversee excavation, service trenching, stump removal, site grading or blasting within, or adjacent to, the tree protection areas (TPAs).
5. Root & branch pruning and protection: a) Any tree roots or branches damaged during site work shall be pruned back to undamaged tissue by the arborist. b) The vertical face of excavated cuts adjacent to the TPAs shall be securely covered with non-permeable fabric by the project arborist to prevent soil desiccation and erosion.

6. Mulch and Irrigation: Trees impacted by excavation for site servicing shall be top-dressed throughout their protected root zones with 100 mm of clean tree chip mulch and irrigated once every two weeks during the dry summer period (May to mid-October) to a minimum effective depth of 30cm.
7. Temporary access: If temporary access is required within a tree protection area (TPA), the contractor shall notify the project arborist in advance and review the access requirements and any additional protective measures prescribed by the arborist.
8. Soil armouring: If it is not possible to fence the entire PRZ, the unprotected portion of the PRZ shall be armoured with 3/4" plywood or a temporary cover of geo-textile and 200mm of road-base, moderately compacted with a plate compactor. (See drawing for recommended soil armouring locations.)
9. Storage restrictions: No equipment, materials or excavated soil shall be placed or stored within the TPA.
10. Procedure for rock removal near tree root zones: a. The general contractor will convene a meeting with the arborist and blasting contractor prior to drilling to develop a work plan that limits rock removal impacts to protected trees. b. Where considered necessary by the arborist, alternate rock removal techniques, such as hoe-ramming, shall be used in place of blasting. c. Blasting vibrations in the vicinity of the Tree Protection Areas are not to exceed a measured peak particle velocity of 25 mm/sec. i. Seismometer records will be kept of all blasting within a 30m radius of any tree protection areas for review by the project arborist. ii. Seismometers shall be placed at the outer boundary of the tree protection area closest to the blast zone. d. Use DYNAMITE as the explosive product. No fertilizer-based explosive is permitted, due to its toxicity to tree roots. e. The contractor shall prevent rock debris from the blast site from entering the TPA.

Further site-specific tree protection recommendations and guidance will be required from a certified arborist during site servicing and lot buildout.

I, Tim Adam, hereby certify that: a. I am a qualified environmental professional, as defined in the Riparian Areas Protection Regulation made under the Riparian Areas Protection Act; b. I am qualified to carry out this part of the assessment of the development proposal made by the developer David McAllister; c. I have carried out an assessment of the development proposal and my assessment is set out in this Assessment Report; and in carrying out my assessment of the development proposal, I have followed the assessment methods set out in the Minister’s technical manual to the Riparian Areas Protection Regulation.

5. Encroachment

A major cause of riparian loss and stream degradation is a result of encroachment by adjacent landowners. Human impacts to streams and riparian areas commonly consist of refuse dumping (including yard waste which can introduce invasive species), trampling of vegetation and bank erosion. These effects were noted within the survey area.

To avoid further or future encroachment into the SPEA and SPEA Protection Zone (SPZ) during construction, a high visibility fence will be erected along the SPEA and SPZ boundary prior to clearing, excavation or grading. The no-clearing fence is intended to prevent inadvertent damage or disturbance to the SPEA and SPZ by construction activities.

Once construction has been completed, the no-clearing boundary fence must be replaced with a permanent fence located along or outside SPEA. The permanent fence will, at a minimum, be a post and rail wood fence (1.5 m high) with wire mesh or an alternate design which is acceptable to the QEP.

To protect and maintain the SPEA over the long term (e.g. including all future owners), a “no-disturbance” restrictive covenant should be registered for the SPEA. Alternatively, park dedication of the SPEA area could explored.

I, Tim Adam, hereby certify that: a. I am a qualified environmental professional, as defined in the Riparian Areas Protection Regulation made under the Riparian Areas Protection Act; b. I am qualified to carry out this part of the assessment of the development proposal made by the developer David McAllister; c. I have carried out an assessment of the development proposal and my assessment is set out in this Assessment Report; and in carrying out my assessment of the development proposal, I have followed the assessment methods set out in the Minister’s technical manual to the Riparian Areas Protection Regulation.

6. Sediment and Erosion Control

Erosion and sediment control (ESC) measures should be implemented and monitored during land clearing, grading, and building construction phases of development, as well as during final landscaping, to meet the requirements of the water discharge criteria of the BC Water Quality Guidelines for Aquatic Life (BCWQG-AL) (e.g., prevent the discharge of “waste” into storm sewers or watercourses). Silt fence (keyed-in to the ground) with crushed rock berm as required is to be properly installed and maintained along the outer edge (development side) of the SPEA or SPZ. Sediment and turbid water must be collected and treated within the development area such that water not meeting the BCWQG-AL (e.g., for turbidity or other applicable parameters) is not discharged from the construction site into to Millstream, SPEA, SPZ or into ditches along Atkins Road or any storm sewers (e.g. catch basins).

An environmental monitor (a QEP) should work with the project engineer to prepare a site specific ESC plan in advance of construction. The environmental monitor should review the installation of all erosion and sediment control measures as directed in the ESC plan following clearing, prior to grading, and frequently during the duration of construction. The environmental monitor should monitor the implementation and effectiveness of the ESC plan. Following construction, the environmental monitor should confirm the removal of all temporary ESC measures and final installation of all permanent ESC measures (e.g., seeding).

I, Tim Adam, hereby certify that: a. I am a qualified environmental professional, as defined in the Riparian Areas Protection Regulation made under the Riparian Areas Protection Act; b. I am qualified to carry out this part of the assessment of the development proposal made by the developer David McAllister; c. I have carried out an assessment of the development proposal and my assessment is set out in this Assessment Report; and in carrying out my assessment of the development proposal, I have followed the assessment methods set out in the Minister’s technical manual to the Riparian Areas Protection Regulation.

7. Stormwater Management

Development tends to increase the proportion of impervious surfaces on a parcel of land by converting previously forested or grass covered areas into building structures with roofs and paved surfaces. The associated increase in impervious surfaces can impact the hydrology of a stream, by increasing peak storm flows and decreasing stream base flow. Peak storm flows are increased when rainwater hitting impervious surfaces is collected and directed to the stream as stormwater runoff (as opposed to infiltrating into the ground). Increasing peak storm flows within streams increases the erosion risk posed to stream bed and banks and can increase slope stability concerns. As infiltration of rainwater is reduced, groundwater recharge is reduced and consequently the baseflow of the stream is reduced. Reduced baseflow is particularly significant during the drier summer months when insufficient flow can pose an issue to aquatic life.

Recommendations are provided by Ryzuk Geotechnical Engineering and Material Testing dated March 5, 2019 regarding stormwater management for slope stability. Landscaping features should be constructed such that surface flows are not concentrated to discharge at the slope crest. Alternatively, collected water could be conveyed downslope via secured solid pipe network and discharged onto non-erodible soils. In discussion with the municipal staff, they indicated a preference to discharge stormwater runoff to the ravine and Millstream directly as described in the alternative plan.

Use of the existing ditch along Atkins Road would result in the eventual discharge of stormwater to Millstream with the potential for ground infiltration, nutrient absorption, and particulate filtration within the ditch. Additional enhancements through rock groin placement and in channel planting (bioswale) could improve these results.

The project civil engineer should consider the design and implementation of measures to reduce the total volume of stormwater discharging from the site by planning to maximize infiltration to groundwater if safe to do so geotechnically. Consideration should be given to utilizing additional topsoil on landscaped areas of the site for volume reduction purposes. Roof leaders and foundation drains should be directed to infiltration areas (rock pits) and biofiltration swales (Atkins Ditch).

The results of geotechnical investigations and qualified professional recommendations on slope stability should be taken into consideration when planning groundwater loading, storm water runoff, impervious surface and landscaping features. Surface runoff should be intercepted and directed away from the existing ravine to avoid slope erosion and instability.

I, Tim Adam, hereby certify that: a. I am a qualified environmental professional, as defined in the Riparian Areas Protection Regulation made under the Riparian Areas Protection Act; b. I am qualified to carry out this part of the assessment of the development proposal made by the developer David McAllister; c. I have carried out an assessment of the development proposal and my assessment is set out in this Assessment Report; and In carrying out my assessment of the development proposal, I have followed the assessment methods set out in the Minister’s technical manual to the Riparian Areas Protection Regulation.

8. Floodplain Concerns (highly mobile channel)

There are no floodplain concerns regarding the proposed development and Millstream. The channel shows indications of channel mobility within the ravine. However, Millstream is highly unlikely to impact the proposed development given the width of the calculated SPEA, the height of the ravine, and the proposed tree replanting on the ravine slope.

I, Tim Adam, hereby certify that: a. I am a qualified environmental professional, as defined in the Riparian Areas Protection Regulation made under the Riparian Areas Protection Act; b. I am qualified to carry out this part of the assessment of the development proposal made by the developer David McAllister; c. I have carried out an assessment of the development proposal and my assessment is set out in this Assessment Report; and in carrying out my assessment of the development proposal, I have followed the assessment methods set out in the Minister’s technical manual to the Riparian Areas Protection Regulation.

Section 5. Environmental Monitoring

Environmental monitoring of the Site during the future construction phase, once the development plan has been finalized, will be conducted to support the implementation of the recommendations outlined within this report. This RAPR Assessment Report has been completed early in the development planning for this Site, with the objective of determining the “development envelopes” for a subdivision of the existing lot. Once the streamside protection and enhancement area (SPEA) is set aside and protected, the measures to protect the SPEA must be maintained though the duration of all stages of redevelopment including construction and restoration works.

Prior to clearing and site preparation works, the SPEA and SPZ boundary is to be marked on the ground (e.g. staking) and a “no-clearing, no work, no access boundary” snow fence is to be erected along the SPZ boundary. The installation of the no-clearing boundary fence is to be inspected regularly by the environmental monitor to verify that the SPEA and SPZ are protected, before and after clearing as well as during the excavation at the site. A silt fence should also be installed and maintained adjacent to the no-clearing boundary fence, inside the development zone. Once clearing and grading are completed, the completed installation of the permanent SPEA fence is to be inspected.

Post-Construction Report

A post-development report must be prepared by the environmental monitor, documenting the measures taken to establish the SPEA on the ground and the implementation of measures to protect the SPEA (e.g. SPEA encroachment avoidance, sediment and erosion control, and stormwater management) described above. The post-development report will also describe the effectiveness of the SPEA protection measures, detail steps taken to correct problems during development, and verify compliance with the establishment and protection of the SPEA.