A Tree Preservation Plan for a Residential Civil Engineering Project is a critical component that outlines the strategies and measures for preserving existing trees on the development site. Preserving mature trees provides ecological benefits (like improving air quality and supporting local wildlife), enhances the aesthetic quality of the residential environment, and may be required by local municipalities or zoning codes.
The Tree Preservation Plan should detail the trees to be preserved, the methodology for their protection during construction, and any necessary mitigation measures. Here’s a comprehensive outline for creating a Tree Preservation Plan for a residential development.
Introduction to the Tree Preservation Plan
Project Overview
- Project Description: Provide a brief description of the residential development, including the scope (e.g., number of units, type of housing), location, and the size of the site.
- Objectives of the Tree Preservation Plan: State the primary goal of the plan, which is to protect mature trees during construction while ensuring the long-term health and viability of those trees that will remain on the site.
Regulatory Context
- Local Ordinances and Codes: Reference any local tree preservation regulations or ordinances that the project must comply with, including specific tree protection requirements, penalties for non-compliance, or incentives for tree preservation.
- Environmental Considerations: Discuss any environmental reviews or requirements related to tree preservation that the project may be subject to (e.g., if the site is located in an environmentally sensitive area, such as a riparian zone or wildlife corridor).
Tree Inventory and Assessment
Tree Inventory
- Survey of Existing Trees: Conduct a detailed survey of all existing trees on the site. The survey should include:
- Tree species
- Diameter at Breast Height (DBH)
- Tree height and canopy spread
- General health and condition of the tree
- Any visible signs of disease or pests
- Tree Location Mapping: Map the location of each tree on a site plan (to scale), identifying the location of trees that are to be preserved and those that may need to be removed due to construction.
- Tree Protection Zones (TPZ): Identify the Tree Protection Zone (TPZ), which is typically the area around the tree (often defined as a radius equal to the tree’s DBH in feet) that must be kept free of construction activity to avoid damage to the roots.
Tree Condition Evaluation
- Health Assessment: Assess the health of each tree. Trees in poor condition or those that present a safety hazard (e.g., dead or dying trees) may need to be removed.
- Structural Integrity: Consider the stability of large trees, especially in areas of construction where excavation or grading may affect root zones.
Critical Root Zone (CRZ)
- Root Protection: Identify the Critical Root Zone (CRZ) for each tree, which is the area of the soil that contains the tree’s most vital roots. This zone is typically 1.5 feet for every inch of DBH for mature trees. These areas should be carefully protected during construction to prevent root damage.
Tree Preservation Methodology
Protection Measures
- Tree Protection Fencing:
- Install tree protection fencing around the TPZ or CRZ before any construction begins to prevent equipment and materials from encroaching on these areas.
- Fencing should be sturdy (e.g., chain-link or plywood) and clearly marked to ensure workers and contractors understand the protected areas.
- Root Protection:
- Root Zone Isolation: Avoid trenching, grading, or excavation near the tree’s roots, particularly within the CRZ. Use air-spading techniques if digging is necessary within the root zone to minimize root damage.
- Avoid Compaction: Prevent heavy equipment from driving or storing materials over tree roots, which can compact the soil and harm the root system.
- Pruning and Maintenance:
- Prune trees before construction begins, if necessary, to remove any dead or overhanging branches that could be damaged during construction.
- Ensure that pruning is done in accordance with accepted arboricultural standards to avoid stressing the tree.
- Watering and Fertilization:
- Implement a post-construction tree care plan, which includes regular watering, mulching, and fertilization to ensure the health of trees that are being preserved.
- Special care may be needed if the construction site has disrupted natural drainage or water supply to the trees.
Impact of Construction on Trees
Grading and Excavation
- Grading Impact: Analyze the impact of proposed grading on the trees to be preserved. Grading around tree roots can lead to erosion, compaction, or changes in water availability.
- Soil Compaction: Prevent soil compaction around tree roots by directing traffic away from tree root zones and using construction mats to distribute load when machinery needs to cross near trees.
Utilities and Infrastructure
- Utility Placement: Minimize interference with tree root systems when planning for utilities (e.g., water, sewer, electrical, or stormwater lines). Use directional boring or trenchless technology when placing utility lines near trees to avoid root disruption.
- Stormwater Drainage: Ensure that stormwater management systems (such as swales, ponds, or detention basins) are located far from protected tree areas to avoid altering the natural water regime of trees.
Tree Removal Criteria
- Necessity for Removal: Identify trees that need to be removed for construction. This can include trees that interfere with planned structures (homes, roads, utilities) or those that are unhealthy beyond repair.
- Mitigation for Removal: Provide a plan for replacing trees that must be removed. This may include planting new trees as part of the landscaping plan, typically in a 2:1 or 3:1 replacement ratio depending on local requirements.
- Tree Replacement and Mitigation: Detail the species, size, and location for tree replacements, especially in terms of how new trees will be integrated into the residential landscape.
Tree Maintenance and Post-Construction Care
Ongoing Tree Care Plan
- Watering and Irrigation: Implement a post-construction watering plan to ensure that preserved trees are adequately watered during the dry seasons. Consider using an irrigation system if necessary.
- Mulching: Apply mulch around the base of the tree to retain moisture, reduce soil compaction, and maintain temperature stability. Ensure mulch is not piled up against the tree trunk to avoid rot.
- Pruning and Monitoring: Regularly monitor the trees for signs of distress (e.g., leaf drop, discolored leaves) and prune them as needed to ensure healthy growth.
Post-Construction Inspection
- Conduct a post-construction inspection after the final stages of development to evaluate the success of the tree preservation efforts. Address any issues, such as soil compaction or water drainage problems, that may affect tree health.
Tree Preservation Plan Implementation and Timeline
Pre-Construction Phase
- Survey and Assessment: Complete the tree inventory, health assessment, and mapping of the trees on-site.
- Establish Protection Zones: Install tree protection fencing around TPZ and CRZ areas before construction begins.
- Tree Pruning: Conduct necessary pruning for safety and health of preserved trees.
Construction Phase
- Enforce Protection: Ensure tree protection measures are maintained throughout construction, including limiting access to TPZ areas and preventing equipment from entering root zones.
- Monitor for Compliance: Regularly inspect tree protection zones to ensure compliance with the preservation plan.
Post-Construction Phase
- Site Rehabilitation: Address any areas where tree protection may have been compromised, including soil aeration or irrigation adjustments.
- Ongoing Care: Implement ongoing tree care, including watering, mulching, and periodic inspections, to ensure the long-term success of tree preservation efforts.
Conclusion and Summary of Key Recommendations
- Summary of Tree Preservation Goals: Reiterate the importance of tree preservation for the environmental, aesthetic, and social value it brings to the community.
- Tree Mitigation Plans: Ensure that any tree removal is justified and that mitigation (e.g., replanting) occurs as needed.
- Recommendations for Future Monitoring: Recommend a monitoring schedule to ensure that trees remain healthy and protected long after construction is completed.
Supporting Documents and Attachments
- Tree Inventory Map: A detailed map showing the location of each tree, including those to be preserved and those proposed for removal.
- Tree Protection Zone Plan: A site plan indicating the areas around each tree to be preserved (including TPZ and CRZ areas) and the installation of protective fencing.
- Tree Replacement Schedule: A schedule that outlines the specific trees that will be replaced and where new plantings will occur.
- Mitigation and Care Instructions: Detailed instructions for post-construction tree care, including watering, pruning, and fertilization plans.
Tree Preservation Plan will ensure that valuable trees are protected and maintained throughout the construction process and that the residential development integrates harmoniously with the natural environment. Proper tree preservation not only supports sustainability but also enhances the quality of life for future
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