Attachment 2: Civil Plans - West Park at Thetis Grading and Erosion Control

West Park at Thetis - Civil Erosion & Sediment Control Plan

Project: Limona Construction Project Number: 2016-2253-00 Drawing Number: 2253-00-C-901 Sheet: 1 Scale: 1:500

[Diagram: Erosion and sediment control map illustrating construction phasing (Phases 1-6) and the locations of silt fences, swales, and sediment control features.]

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Site Notes and Phasing

• Phase 1 through Phase 6
• Common Property Play Area
• Easement Plan EPP92347
• Stabilized Construction Entrance: See Detail 4 C-902
• Silt Fence (Typ): See Detail 2 C-902
• Sediment Control Ditch: See Detail 1 C-902
• Swale: See Detail 3 C-902
• Temporary Lawn Basin Discharging to Phase 1 Storm
• Temporary Lawn Basin Discharging to Phase 3 Storm
• General Note: Grade road to drain to ditch/swale during road construction. Once road paved, deactivate ditch/swale and protect catchbasins using filter inserts.

Design Flow Specifications

• Flow 1: Design Flow 10yr = 63.1 L/S, Velocity = 0.925 m/s, 1 m BW, 3H:1V, 25kg
• Flow 2: Design Flow 10yr = 20.04 L/S, Velocity = 0.44 m/s, 1 m BW, 3H:1V, 10kg

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West Park at Thetis - Civil Notes & Details

Project: Limona Construction Project Number: 2016-2253-00 Drawing Number: 2253-00-C-902 Sheet: 2 Scale: AS SHOWN

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Detail 1: Sediment Control Ditch

[Diagram: Cross-section and profile view of a sediment control ditch with riprap and check dams.]

Ditch/Swale Dimensions

Detail 2: Silt Fence Detail

[Diagram: Side view and profile of silt fence construction including posts, geotextile fabric, and embedment.]

Silt Control Notes:

1. Permittivity of geofabric to be ~ 10L/S/m2
2. Splices to be at posts such that each piece is wrapped fully around post.
3. Silt fence to have an efficiency >75%. Where efficiency is less than this employ successive fences to reach the desired amount.
4. At completion of work silt to be removed and disposed of.

Detail 3: Swale Cross Section

[Diagram: Cross-section of a 2.4m wide, 0.3m deep swale.]

Detail 4: Stabilized Construction Entrance & Tire Wash

[Diagram: Plan and section views of a construction entrance featuring a wheel wash sump and swale for runoff management.]

Sediment & Erosion Control Notes:

The contractor shall be responsible for maintenance and inspection of all sediment and erosion control facilities, shall provide regular inspection reports to the civil engineer and shall coordinate any remediation required by the engineer.

All practical and necessary effort should be taken during construction to control and prevent erosion and the transport of sediment to surface drains, surface water or onto other property by any or all of the following methods:

1. Construct a stabilized construction entrance and wheel wash.
2. Direct all stormwater discharge to existing storm system throughout construction.
3. Stabilized construction entrance to remain in place until excavation and grading is complete and all surfaces are stabilized.
4. Temporary sediment and erosion control measures such as silt fence and street sweeping are to be employed wherever necessary to prevent migration of sediment off-site. Nearby off-site streets as well as completed on-site paving must be kept clean through regular street sweeping. During construction, these measures shall be regularly inspected and replaced or employed as required or as directed by the civil engineer. Silt fence to be installed down grade from excavated or disturbed areas until surfaces are stabilized.
5. During dry weather, sprinklers are to be placed adjacent to excavation or grading activities to prevent dust from leaving the site.
6. Dust control fabric to be installed on temporary construction fencing as required to prevent dust migration.
7. All drainage inlets shall be protected from sedimentation with filter cloth during construction. This protection shall be inspected weekly and after any significant rainfall event. Filter fabric shall be replaced as it becomes blinded with sediment or damaged, or as directed by the civil engineer.
8. It is the contractor's responsibility to ensure grades are maintained in such as way that all stormwater runoff is directed toward stormwater containment facilities.
9. No stockpiling of granular material is permitted on paved surfaces. Any existing material being stockpiled as part of site grading exercises shall be placed within 3 days or surrounded by silt fence to contain erosion. Silt fence shall be installed down grade from pre-load material.
10. Compaction and/ or vegetation of disturbed ground surfaces shall be accomplished as soon as possible and practical.
11. The use of any construction equipment that leaks excessive amounts of fuel, oil or hydraulic fluid is prohibited.
12. Any spillage of hazardous materials or materials which may be detrimental to the environment must be cleaned up immediately and the proper authorities must be notified, as required by law.
13. Upon completion of construction, any accumulated sediment is to be removed from all sump inlets, catch basins and storm manholes.
14. Upon completion of construction, temporary sediment and erosion control measures such as silt fence, shall be removed.
15. Monitor sediment levels in stormceptor units after rainfall events. Clean as required during construction and when construction is complete.

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West Park at Thetis - Civil Typical Sections Plan View - PH 3-6

Project: Limona Construction Project Number: 2016-2253-00 Drawing Number: 2253-00-C-801 Sheet: 1 Scale: 1:500

[Diagram: Plan view highlighting Phases 3 through 6 and marking the location and orientation of cross-sections A-A through F-F.]

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Labels

• Greenspace
• Common Property Play Area
• Easement Plan EPP92347
• Section Markers 1 through 6 (corresponding to Sections A-A to F-F)

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West Park at Thetis - Civil Typical Sections Phase 3-6

Project: Limona Construction Project Number: 2016-2253-00 Drawing Number: 2253-00-C-802 Sheet: 2 Scale: AS SHOWN

Revision Table

Typical Sections

[Charts: Six profile diagrams (Section A-A, B-B, C-C, D-D, E-E, and F-F) comparing existing ground elevations to typical subgrade design elevations across various stations.]

• Section 1: A-A (H 1:500 V 1:250)
• Section 2: B-B (H 1:500 V 1:250)
• Section 3: C-C (H 1:500 V 1:250)
• Section 4: D-D (H 1:500 V 1:250)
• Section 5: E-E (H 1:500 V 1:250)
• Section 6: F-F (H 1:500 V 1:250)