DEPARTMENT: Development Services
SUBJECT: TPV 19-009 Tree Preservation Variance for Gombert Tract (Cielo Ranch) Units 2 & 3
SUMMARY:
Request by Mr. Jon Robinson, RLA, 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”, general located on Ralph Fair Road and Old Paseo Way Staff recommends approval. (Herminio Griego, (210) 207-6042, Herminio.griego@sanantonio.gov, Development Services Department)
BACKGROUND INFORMATION:
Project A/P# 2362487
Council District: 8
Consultant: Jon Robinson, RLA with Horizon Design Landscape Architecture
Staff Coordinator: Herminio Griego, Assistant City Arborist, (210) 207-6042
ANALYSIS:
The Development Services Department (DSD) has reviewed the information presented in Mr. Jon Robinson’s letter dated January 11, 2019 letter received on January 16, 2019.
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 and Riparian Buffer in excess of the 80% and 100% minimum preservation of protected significant and heritage trees respectively in place under the 2015 Tree Preservation Ordinance for development of the Gombert Tract (Cielo Ranch) Units 2 and 3 project. DSD staff does agree with the applicant’s request to mitigate via planting for tree survey inches determined to be below 80% significant and 100% heritage tree preservation for the following reasons:
1. Existing site conditions - The project includes 38.4 acres with the construction of 3,350 linear feet of Desperado Trail, 107 new single family residential lots, a community amenity center, a bridge over the regulatory floodplain and associated drainage and storm water improvements. The front portion of the property includes approximately 49,005 square feet of floodplain with a 30’ Riparian Buffer. The floodplain includes 757 inches of Significant Trees and 128 inches of Heritage Trees. The Riparian Buffer includes 393.5 inches of Significant Trees and one 23” Heritage Tree. A significant amount of earthwork is required to convey the water appropriately in support of the bridge across the floodplain and Desperado Trail. The necessary earthwork will result in tree removal in the floodplain and Riparian Buffer below the UDC requirements.
2. Due to existing site conditions, bridge and road construction Riparian Buffer the project is unable to preserve the minimum 80% of Significant and 100% of heritage trees surveyed in the floodplain and riparian Buffer areas. The project and preservation data are presented in the table below:
|
|
Riparian Buffer |
Floodplain |
Units |
|
Significant Tree Survey Data |
|
|
|
|
Total Inches |
369.5 |
757 |
Inches |
|
Preserved _ Credit Inches |
9.5 |
432 |
Inches |
|
Removed Inches |
360 |
325 |
Inches |
|
Preserved % |
56.9 |
57.1 |
% |
|
Required % |
80 |
80 |
% |
|
|
|
|
|
|
Heritage Tree Survey Data |
|
|
|
|
Total Inches |
24 |
128 |
Inches |
|
Preserved Inches |
0 |
88 |
Inches |
|
Removed Inches |
24 |
40 |
Inches |
|
Preserved % |
0 |
68.8 |
% |
|
Required % |
100 |
100 |
% |
|
|
|
|
|
|
Mitigation |
|
|
|
|
Significant |
286.1 |
173.6 |
Inches |
|
Heritage |
72 |
120 |
Inches |
|
Subtotal |
358.1 |
293.6 |
Inches |
|
Final total |
|
652 |
Inches |
3. Required mitigation for the tree survey is 652 Inches (inches as depicted in the table above:
4. Tree mitigation and canopy diversity - The applicant opted to provide mitigation above and beyond the minimum required in the UDC as identified below: The project will meet the Riparian Buffer tree survey mitigation requirements as follows:
a. Upsizing the two (2) trees per lot required by the UDC from 1.5” to 4”
b. Re-seeding 39,920 SF of disturbed area within the flood plain and adjacent Riparian Buffer
c. Reclaiming disturbed areas by drill seeding native seed mix and ensuring 85% establishment.
|
|
FLOODPLAIN MITIGATION MECHANISM |
MITIGATION |
APPLIED TOWARD |
|
A. |
(13) Addtl. 4” Cedar Elms on Desperado Trail |
52 Cal. Inches |
Flood Plain Mitigation |
|
B. |
(15) Addtl. 4” Live Oaks on Desperado Trail |
60 Cal. Inches |
Flood Plain Mitigation |
|
C. |
(42) Addtl. 2.5” Mtn. Laurels on Desperado Tr. |
105 Cal. Inches |
Flood Plain Mitigation |
|
D. |
Re-seed 24,320 SF of area in Flood Plain NOTE: Re-seeding will consist of an approved native seed mix applied by drill seeding and established to 85%. |
147 Cal. Inches |
Flood Plain Mitigation |
|
|
Total Riparian Buffer Mitigation Provided: |
364 Cal. Inches |
|
|
|
Total Riparian Plain Mitigation Required: |
294 Cal. Inches |
|
|
|
Excess Flood Plain Mitigation Provided: |
70 Cal. Inches |
|
|
|
RIPARIAN BUFFER MITIGATION MECHANISM |
MITIGATION |
APPLIED TOWARD |
|
A. |
(18) Addtl. 4” Bur Oaks on Desperado Trail |
72 Cal. Inches |
Protected Tree Mitigation |
|
B. |
(17) Addtl. 4” Shumard Oaks on Desperado Trail |
68 Cal. Inches |
Protected Tree Mitigation |
|
C. |
(19) Addtl. 2.5” Mtn. Laurels on Desperado Tr. |
47.5 Cal. Inches |
Riparian Buffer Mitigation |
|
D. |
Re-seed 15,600 SF of Riparian Buffer NOTE: Re-seeding will consist of an approved native seed mix applied by drill seeding and established to 85%. |
179 Cal. Inches |
Riparian Buffer Mitigation |
|
|
Total Riparian Buffer Mitigation Provided: |
366.5 Cal. Inches |
|
|
|
Total Riparian Buffer Mitigation Required: |
358.1 Cal. Inches |
|
|
|
Excess Riparian Buffer Mitigation Provided: |
8.5 Cal. Inches |
|
|
|
TOTAL EXCESS MITIGATION |
78.5 Cal Inches |
|
Additionally, the Owner will provide or Gombert Tracts Units 2 and 3 a post-development tree canopy of 848,630 SF, equal to 322,101 SF in excess of the minimum required by the UDC and 61.2% of the net project site area.
DSD staff supports the applicant’s request to fall below 80% Significant Tree and 100% Heritage Tree preservation requirements in the 100 year floodplain and Riparian Bufferbased on the conditions of the site, need for appropriate storm water control appertenances, and exceeding mitigation and tree survey and final canopy cover requirements. The proposed Variance Request meets the intent and spirit of the Tree Ordinance therefore, staff recommends approval.