DEPARTMENT: Development Services
SUBJECT: TPV 18-011 Tree Preservation Variance for Union Pacific Railroad San Antonio Intermodal Terminal South Lead
SUMMARY:
Request by Mr. Richard Wilson for approval of a tree preservation variance request from Unified Development Code 35-523 (h), “significant trees shall be preserved at eighty (80) percent and heritage trees at one hundred (100) percent preservation within both the 100-year floodplains and environmentally sensitive areas.” Staff recommends approval. (Herminio Griego, (210) 207-6042, herminio.griego@sanantonio.gov, Development Services Department)
BACKGROUND INFORMATION:
Project A/P# 2322080
Council District: 4
Consultant: Mr. Richard Wilson of HDR, Inc.
Staff Coordinator: Herminio Griego, Assistant City Arborist, (210) 207-6042
ANALYSIS:
The Development Services Department (DSD) has reviewed the information presented in Mr. Wilson’s letter dated January 16, 2018.
The Unified Development Code (UDC) - Article V, Section 35-523 (h), 100-Year Floodplain(s) and Environmentally Sensitive Areas states that, “Significant trees shall be preserved at eighty (80) percent preservation within both the 100-year floodplains and environmentally sensitive areas. Mitigation shall be prohibited in floodplains and environmentally sensitive area except when a variance is granted by the Planning Commission.”
The applicant is requesting a Variance Request to mitigate for removal of surveyed trees within the 100-year floodplain in excess of the 80% minimum preservation of protected trees in place under the 2015 Tree Preservation Ordinance for the construction of the an additional track south and east of the of the existing Laredo Subdivision mainline track. The new track will allow the existing Laredo Subdivision to be the southern lead into the San Antonio Intermodal Terminal (SAIT). Mr. Wilson coordinated with city staff to ensure that the proposed tree mitigation meets desired criteria. In addition, the project team coordinated with Mr. Wilson to ensure that the contractor can preserve as many trees as possible while maintaining a safe work environment and delivering a high quality product. DSD staff does agree with the applicant’s request to mitigate for tree stand below 80% preservation for the following reasons:
1. Project Information - This project will include the construction of a new line on the southeast side of the existing Laredo Subdivision mainline track as it passes the SAIT. The new line will be two miles long and require the addition of approximately 2.6 acres of twenty feet wide right of way, and 4.25 acres of temporary construction easement and forty foot wide site access. The total project will encompass 31 acres including UPRR rights of way on both sides of each track and the property between the two tracks.
The project location and alignment close to the SAIT will optimize the construction of new infrastructure and minimize the disruption of existing infrastructure. This is turn will minimize tree impacts. In addition, the project is limited by the Medina River to the south and west of the project area. These efforts will result in reduced tree loss, construction impacts and inconveniences. In addition, the additional rail capacity will enhance the mainline rail traffic flow and operations.
2. Tree Preservation - Due to the proposed scope of work, the project is unable to preserve the minimum 80% of significant trees within the 100-year floodplain and Environmentally Sensitive Area (ESA). There are 1,120 inches and 52 inches of significant and heritage trees respectively in the floodplain for a total of 1,172 inches of trees.
|
|
Floodplain |
Buffer (Environmentally Sensitive Area) |
Total |
|
Unavoidable Impacts (Removed Inches) |
Significant Trees |
530 |
74 |
604 |
|
|
Heritage Trees |
0 |
0 |
0 |
|
|
|
Preserved Inches |
Significant Trees |
590 |
26 |
616 |
|
|
Heritage Trees |
52 |
0 |
52 |
|
|
|
Total Inches |
Significant Trees |
1120 |
100 |
1220 |
|
|
Heritage Trees |
52 |
0 |
52 |
|
|
|
Percent Preserved |
Significant Trees |
53 |
26 |
- |
|
|
Heritage Trees |
100 |
N/A |
- |
|
|
|
Preservation Inches Required |
Significant Trees |
896 |
80 |
- |
|
|
Heritage Trees |
52 |
N/A |
- |
|
|
|
Mitigation Inches Required |
Significant Trees |
306 |
54 |
360 |
|
|
Heritage Trees |
0 |
0 |
0 |
In the floodplain, fifty-two (52) inches (100%) percent of the heritage trees will be preserved. In addition, there are 604 inches of significant trees (See table above). Five hundred and thirty inches (47%) will be removed and 590 inches (53%) will be preserved. In the Environmentally Sensitive Area (ESA), there are 100 inches of significant trees. Seventy-four inches (74%) will be removed and 26 inches (26%) preserved. Both, the floodplain and the ESA preservation percentages are less than the required eighty (80%) percent preserved. The floodplain and ESA require 306 inches and 54 inches of mitigation respectively.
The required total mitigation for the significant trees in the floodplain and ESA equates to 360 diameter inches. No heritage trees will be removed in either the floodplain or the buffer.
3. Tree mitigation -
a. A grand total of 360 diameter inches of trees will be mitigated by paying in to the Tree Mitigation Fund $72,000 (360 inches x $200 per inch).
b. In addition, will be required to:
i. Seed all of disturbed area, an estimated 240,000 square feet (240,000 ft2), with a native grass seed mix consisting of grasses, legumes and wildflowers native to the San Antonio area. For safety reasons, the drill-seed technique will be used on slopes equal to or less than 3:1. Steeper areas will be seeded using the hydro-mulch technique;
ii. Establish 85% of the native seed mix and
iii. Make best efforts to preserve the native understory in areas where trees are preserved.
DSD staff supports the applicant’s request to fall below 80% of tree survey preservation requirements based on the project type, conditions of the site and design constraints. The proposed Variance Request meets the intent and spirit of the Tree Ordinance therefore, staff recommends approval.