430.210 Site Development Protection and Mitigation.
A. Protection of Natural Resources During Site Development. During development of any site containing a designated natural resource, the following standards shall apply:
(1) Work areas shall be marked to reduce potential damage to the WQR and/or HCA.
(2) Trees in a WQR or HCA shall not be used as anchors for stabilizing construction equipment.
(3) Native soils disturbed during development shall be conserved on the property.
(4) An erosion and sediment control plan is required and shall be prepared in compliance with requirements set forth in Subsection 430.220 and the City of Wood Village Public Works Standards.
(5) Site preparation and construction practices shall be followed that prevent drainage of hazardous materials or erosion, pollution, or sedimentation to any WQR adjacent to the project area.
(6) Stormwater flows that result from proposed development within and to natural drainage courses shall not exceed predevelopment flows.
(7) Prior to construction, the WQR and/or HCA that is to remain undeveloped shall be flagged, fenced or otherwise marked and shall remain undisturbed. Such markings shall be maintained until construction is complete.
(8) The construction phase of the development shall be done in such a manner as to safeguard the resource portions of the site that have not been approved for development.
(9) Where practicable, lights shall be placed so that they do not shine directly into any WQR and/or HCA location. The type, size and intensity of lighting shall be selected so that impacts to habitat functions are minimized.
(10) All work on the property shall conform to a Construction Management Plan prepared according to Section 430.190.
B. General Standards for Required Mitigation. Where mitigation is required by this Section for disturbance to a WQR and/or HCA, the applicable sections of Table 2 and the following general standards shall apply:
(1) Disturbance.
(a) Designated natural resources that are affected by temporary disturbances shall be restored, and those affected by permanent disturbances shall be mitigated as applicable.
(b) Landscape plantings are not considered to be disturbances, except for those plantings that are part of a non-exempt stormwater facility; e.g., raingarden or bioswale.
(2) Required Plants. Unless specified elsewhere in this Section, all trees, shrubs and ground cover planted as mitigation shall be native plants, as identified on the City Plant List. Applicants are encouraged to choose particular native species that are appropriately suited for the specific conditions of the planting site; e.g., shade, soil type, moisture, topography, etc. Plant size, spacing and diversity will be approved through discretionary review by the City. The minimum ratio of mitigation shall be 2:1.
(3) Location of Mitigation Area.
(a) On-Site Mitigation. All mitigation vegetation shall be planted on the applicant’s site within the designated natural resource that is disturbed, or in an area contiguous to the resource area; however, if the vegetation is planted outside of the resource area, the applicant shall preserve the contiguous planting area by executing a deed restriction, such as a restrictive covenant.
(b) Off-Site Mitigation.
1. For disturbances allowed within a WQR, off-site mitigation shall not be used to meet the mitigation requirements of this Chapter.
2. For disturbances allowed within an HCA, off-site mitigation vegetation may be planted within an area contiguous to the subject-property HCA, provided there is documentation that the applicant possesses legal authority to conduct and maintain the mitigation, such as having a sufficient ownership interest in the mitigation site. If the off-site mitigation is not within an HCA, the applicant shall document that the mitigation site will be protected after the monitoring period expires, such as through the use of a restrictive covenant.
(4) Invasive Vegetation. Invasive nonnative or noxious vegetation shall be removed within the mitigation area prior to planting, including, but not limited to, species identified as nuisance plants on the City Plant List.
(5) Ground Cover. Bare or open soil areas remaining after the required tree and shrub plantings shall be planted or seeded to 100% surface coverage with grasses or other ground cover species identified as native on the City Plant List. Revegetation shall occur during the next planting season following the site disturbance.
(6) Tree and Shrub Survival. A minimum of 80% of the trees and shrubs planted shall remain alive on the second anniversary of the date that the mitigation planting is completed.
(a) Required Practices. To enhance survival of the mitigation plantings, the following practices are required:
1. Mulch new plantings to a minimum of 3-in depth and 18-in diameter to retain moisture and discourage weed growth.
2. Remove or control nonnative or noxious vegetation throughout the maintenance period.
(b) Recommended Practices. To enhance survival of tree replacement and vegetation plantings, the following practices are recommended:
1. Plant bare root trees between December 1 and April 15; plant potted plants between October 15 and April 30.
2. Use plant sleeves or fencing to protect trees and shrubs against wildlife browsing and the resulting damage to plants.
3. Water new plantings at a rate of 1 inch per week between June 15 and October 15 for the first 2 years following planting.
(c) Monitoring and Reporting. Monitoring of the mitigation site is the ongoing responsibility of the property owner. Plants that die shall be replaced in kind as needed to ensure the minimum 80% survival rate. The City may require a maintenance bond to cover the continued health and survival of all plantings. A maintenance bond shall not be required for land use applications related to owner-occupied single-family residential projects. An annual report on the survival rate of all plantings shall be submitted for 2 years.
(7) Light Impacts. Where practicable, lights shall be placed so that they do not shine directly into any WQR and/or HCA location. The type, size and intensity of lighting shall be selected so that impacts to habitat functions are minimized and are subject to City review.
C. Mitigation Requirements for Disturbance within WQR.
(1) The requirements for mitigation vary depending on the existing condition of the WQR on the project site at the time of application which will be assessed in accordance with the categories established in Table 2. When disturbances within a WQR is approved according to the standards of this Section, the disturbance shall be mitigated according to the requirements outlined in Table 3 and the standards established in Section 430.190 E. Limitations and Mitigation for Disturbance of an HCA.
When disturbances within an HCA are allowed, the City shall remove the HCA designation from such disturbance areas on the WQ Map.
(2) Mitigation Requirements for Disturbance in an HCA. To achieve the goal of reestablishing forested canopy that meets ecological values and functions when development intrudes into an HCA, tree replacement and vegetation planting is required according to the following standards, unless the planting is also subject to wetlands mitigation requirements imposed by state and federal law.
These mitigation options apply to tree removal and/or site disturbance in conjunction with development activities that are otherwise permitted. They do not apply to situations in which tree removal is exempt.
An applicant shall meet the requirement of Mitigation Option 1 or 2, whichever results in more tree plantings; except that where the disturbance area is 1 acre or more, the applicant shall comply with Mitigation Option 2 as shown in Table 3 below.
Wastewater treatment plants, raw water intakes, pump stations, transmission mains, conduits or service lines, terminal storage reservoirs, and outfall devices may be built, expanded, repaired, maintained, reconfigured, rehabilitated, replaced, or upsized in accordance with the following criteria:
(a) Such projects shall not be required to avoid the resource area provided that, where practicable, the project does not encroach closer to a protected water feature than existing operations and development; or, for new projects where there are no existing operations or development, provided that the project does not encroach closer to a protected water feature than practicable.
(b) Best management practices will be employed that accomplish all of the following:
1. Account for watershed assessment information in project design.
2. Minimize the trench area and tree removal within the resource area.
3. Utilize and maintain erosion controls until other site stabilization measures are established, post-construction.
4. Replant immediately after backfilling, or as soon as effective.
5. Preserve wetland soils and retain soil profiles.
6. Minimize compactions and the duration of the work within the resource area.
7. Complete in-water construction during appropriate seasons, or as approved within requisite federal or State permits.
8. Monitor water quality during the construction phases, if applicable.
9. Implement a full inspection and monitoring program during and after project completion, if applicable.
Size of Tree to be Removed (inches in diameter) | Number of Trees and Shrubs to be Planted |
|---|---|
6 to 12 | 2 trees and 3 shrubs |
13 to 18 | 3 trees and 6 shrubs |
19 to 24 | 5 trees and 12 shrubs |
25 to 30 | 7 trees and 18 shrubs |
over 30 | 10 trees and 30 shrubs |
(c) Mitigation Option 1. This mitigation requirement is calculated based on the number and size of trees that are removed from the site. Trees that are removed from the site shall be replaced as shown in Table 3. Conifers shall be replaced with conifers. Bare ground shall be planted or seeded with native grasses or herbs. Nonnative sterile wheat grass may also be planted or seeded, in equal or lesser proportion to the native grasses or herbs.
(d) Mitigation Option 2. This mitigation requirement is calculated based on the size of the disturbance area within an HCA. Native trees and shrubs are required to be planted at a rate of 5 trees and 25 shrubs per 500 sq ft of disturbance area. This is calculated by dividing the number of square feet of disturbance area by 500, multiplying that result times 5 trees and 25 shrubs, and rounding all fractions to the nearest whole number of trees and shrubs.
For example:
For 330 sq ft of disturbance area: 330 ÷ 500 = 0.66, and 0.66 x 5 = 3.3, so 3 trees must be planted. 0.66 x 25 = 16.5, so 17 shrubs must be planted. Bare ground shall be planted or seeded with native grasses or herbs. Nonnative sterile wheat grass may also be planted or seeded, in equal or lesser proportion to native grasses or herbs.
D. Limitations and Mitigation for Disturbance of HCA.
(1) Discretionary Review to Approve Additional Disturbance within an HCA. An applicant seeking discretionary approval to disturb more of an HCA than is allowed shall submit an Impact Evaluation and Alternatives Analysis and shall be subject to the approval criteria provided in ZDC Chapter 510.100 Type I Administrative Process.
(2) Discretionary Review to Approve Mitigation that Varies the Number and Size of Trees and Shrubs within an HCA. An applicant seeking discretionary approval to proportionally vary the number and size of trees and shrubs required to be planted, but who will comply with all other applicable provisions, shall be subject to the following process:
(a) The applicant shall submit the following information:
1. A calculation of the number and size of trees and shrubs the applicant would be required to plant according to this Section.
2. The number and size of trees and shrubs that the applicant proposes to plant.
3. An explanation of how the proposed number and size of trees and shrubs will achieve, at the end of the third year after initial planting, comparable or better mitigation results than would be achieved if the applicant complied with all of the requirements of this Section. Such explanation shall be prepared and signed by a knowledgeable and qualified natural resource professional or a certified landscape architect. It shall include discussion of site preparation including soil additives, removal of invasive and noxious vegetation, plant diversity, plant spacing, and planting season; and immediate post-planting care, including mulching, irrigation, wildlife protection, and weed control.
4. A mitigation, site-monitoring, and site-reporting plan.
(b) Approval of the request shall be based on consideration of the following:
1. Whether the proposed planting will achieve, at the end of the third year after initial planting, comparable or better mitigation results than would be achieved if the applicant complied with all of the requirements of this Section.
2. Whether the proposed mitigation adequately addresses the plant diversity, plant survival, and monitoring practices established in this Section.