City Council members said they plan to pass next Tuesday on first reading a new vegetative ordinance for construction on steep slopes. It would go into effect on July 1 and be reviewed after a year.
Chairman Chip Henderson said he also wants action on a recidivism ordinance, in which there would be penalties against developers who repeatedly violate regulations.
City Councilman Darrin Ledford said, "It's not a magic pill, but it's a great step forward."
He said the ordinance "encourages a stay away from steep slopes mentality" and he said it called for retention of existing trees and shrubs, planting of new trees and use of native species.
In earlier discussions, some citizens pushed for a ban on building on steep slopes and lowlands. Members of the Home Builders Association were strongly opposed.
Outgoing Councilman Jerry Mitchell, who has been pushing for action on the topic, said he would have preferred that low-lying areas also get protections. In his hilly District 2, citizens have complained about projects in which hillsides were carved out and left bare and muddy for extended periods.
AN ORDINANCE AMENDING CHATTANOOGA CITY CODE, PART II, CHAPTER 31, BY ADDING A NEW SECTION 31- 324.3, VEGETATIVE PLANTING REQUIREMENTS WHEN STEEP SLOPES ARE DISTURBED, A NEW SECTION 31- 324.4, STEEP SLOPE VEGETATION POLICY AND PLANTING REQUIREMENTS, AND A NEW SECTION 31- 324.5, INCENTIVES FOR PRESERVATION OF EXISTING TREES.
WHEREAS, the Chattanooga City Council has requested review and reporting on the development of Steep Slopes in the City of Chattanooga due to numerous complaints from citizens about infill development in residential and commercial areas due to the construction which has occurred on ridges and valleys in our City; and WHEREAS, the Regional Planning Agency staff and development professionals have provided comments on the vegetative planting requirements and vegetation policies that should be adopted by the City when steep slopes are disturbed and how existing trees should be preserved in such areas to avoid flooding and runoff issues which are exacerbated by the removal of existing vegetation by new land disturbance during and after development. NOW, THEREFORE, BE IT ORDAINED BY THE CITY COUNCIL OF THE CITY OF CHATTANOOGA, TENNESSEE: SECTION 1. That Chattanooga City Code, Part II, Chapter 31, be amended by adding a new Section 31-324.3, entitled Vegetative Planting Requirements when Steep Slopes are disturbed as follows:
Sec. 31-324.3. Vegetative Planting Requirements when Steep Slopes are disturbed. Steep slopes shall be defined as being slopes of thirty-three (33%) percent or more. Slopes that have been cleared and graded with thirty-three (33%) percent or higher slope may have to be compacted, and may require a certified engineer design to ensure slope stability which may require analysis of vegetative planting. A) All residentially zoned properties containing steep slopes shall adhere to following vegetative replanting requirements for areas with disturbed steep slopes as indicated below. A diverse, multiple canopy planted area provides the maximum stormwater mitigation and it is recommended that all steep slopes provide a simple ratio as outlined in the following charts that includes required numbers of trees, shrubs, evergreen trees, all underplanted with a herbaceous ground surface layer. These regulations apply to lots where the proposed land disturbing activity is disturbed based upon the following lot sizes: Detached Building Development Requirements (Single Family Homes) Max. Area of Steep Slope Req’d Plant Coverage Lot Size w/o Mitigation Based Upon Area
3,000 - 5,000 ft2 Values 1,000 SF Min 1,200 SF/Coverage
5001 ft2 - 7,500 ft2 Values 2,000 SF. Min 1,200 SF/Coverage
7,501 ft2 - 10,000 ft2 Values 2,500 SF. Min 1,200 SF/Coverage
10,001 ft2 - 25,000 ft2 Values 4,000 SF. Min 1,200 SF/Coverage
25,001 ft2 – 35,000 ft2 Values 7,000 SF. Min 1,200 SF/Coverage
35,001 ft2 – 1.00 acres 12,000 SF. Min Values 1,200 SF/Coverage
1.00 acres – Greater Values 20% or greater Min 1,200 SF/Coverage Values
Attached Building Development Requirements (Duplexes, Townhomes, Apartments) Max. Area of Steep Slope Req’d Plant Coverage w/o Mitigation Based upon Area
3,000 - 7,500 ft2 2,000 SF Min 1,000 SF/Coverage Values
7,501ft2 - 10,000 ft2 3,000 SF Min 1,000 SF/Coverage Values
10,001ft2 - 25,000 ft2 5,000 SF Min 1,000 SF/Coverage Values
25,001ft2 – 35,000 ft2 10,000 SF Min 1,000 SF/Coverage Values
35,001 ft2 – 1.00 acres 15,000 SF Min 1,000 SF/Coverage Values
1.01 acres – Greater 20% or greater of lot Min 1,000 SF/Coverage Values
These regulations shall adhere to all R-1, R-2, R-3, R3MD, R-4, R5, RTZ, RZ1, and RT1 zoned properties.
SECTION 2. BE IT FURTHER ORDAINED, that Chattanooga City Code, Part II, Chapter 31, be amended by adding a new Section 31-324.4, entitled Steep Slope Vegetation Policy and Planting Requirements as follows: Sec. 31-324.4. Steep Slope Vegetation Policy and Planting Requirements. The following tree planting requirements shall apply in all areas where steep slopes as defined in Section 38-603 are disturbed. Class I Shade Trees: These trees are used to meet the tree planting requirements for large canopy trees. Evergreen trees can be treated as Class I shade trees provided, they meet the minimum maturity height and canopy spread criteria. Class II Shade Trees: These trees are intended to be used for planting as under story canopy and ornamental type trees. Only Class II trees shall be planted under overhead power lines. Evergreen Screening Trees: Screening trees are used for Screening, Evergreen accents, Anchors, and Framing in the landscape.
Shrubs: Shrubs shall be installed at a minimum size of one (1) gallon. Shrubs are used for foundation plantings, accents, mass plantings, hedging, screening, groundcover, ornamental, and habitat. Shrubs will vary in height and spread and shall be spaced accordingly. No shrub plantings shall be planted in overcrowded masses in a single location to meet this ordinance. Groundcovers/Perennials (excludes all turf areas): Groundcovers/Perennials shall be installed at a minimum size of four (4”) inch pots and up. Groundcover/Perennials shall achieve a mature height of 4- 18 inches with a mature spread one (1’) to four (4’) foot diameter. Groundcovers/Perennials are used for groundcover, mass plantings, erosion control, flowering accents, and habitat. Groundcovers/Perennials will vary in height and spread and shall be spaced accordingly. Replacement Trees/Plantings and coverage values: Trees replacement plantings installed in any areas where steep slopes are disturbed shall consist of Class I, Class II Shade Trees and Evergreen Screening Trees, Shrubs and Groundcover/ Perennials with sufficient minimum canopy to meet this requirement. No single tree species shall constitute more than fifty (50%) percent of total trees required. The following coverage values shall be maintained in all replacement plantings where steep slopes have been disturbed. Class I Tree with 20-30’diameter minimum canopy = 500 SF coverage values Class II Tree with 10-20’diameter minimum canopy = 200SF coverage values Evergreen Screening Tree with 8’ mature spread = 50 SF coverage values Shrub with 3-6’ mature height and spread = 20 SF coverage values Groundcover/Perennials with 1-4’ mature spread = 1 SF coverage values *Evergreen Screening Trees, Shrubs, and Groundcover/Perennials may be used for meeting the required tree replacement plantings up to 25%. SECTION 3. BE IT FURTHER ORDAINED that Chattanooga City Code, Part II, Chapter 31, be amended by adding a new Section 31-324.5, entitled Incentives for Preservation of Existing Trees as follows: Sec. 31-324.5. Incentives for Preservation of Existing Trees. The following tree planting requirements and credits for preservation of existing trees shall apply in all areas where steep slopes as defined in Section 38-603 are disturbed.
For lots 25,000 sq. ft. to 1.00 acres developers may receive up to seventy (70%) percent credit for the required tree plantings for all existing tree(s) preserved on slopes equal to or greater than thirty-three (33%) percent. During land disturbance and construction any trees eligible for credit shall be protected, shall be in good health, and shall be at least four (4”) inch (DBH) or greater. For lots 1.01 acres developers may receive up to seventy (70%) percent credit for the required tree plantings for all existing tree(s) preserved on slopes equal to or greater than thirtythree (33%) percent. During land disturbance and construction any trees eligible for credit shall be protected, shall be in good health, and shall be at least four (4”) inch (DBH) or greater. Any tree plantings as required with Article IX of the Landscape Provisions for a development shall count towards meeting these requirements, but such plantings shall not exceed ten (10%) percent of the required coverage required. A ten (10%) percent credit of the required replacement tree plantings will be allowed for using native plant species. All credits utilized for plantings using native species or credits utilized for those trees as would normally be required for meeting the current landscape ordinance shall not cumulatively exceed a twenty (20%) percent reduction towards meeting the coverage requirements. Key Objectives of the Steep Slope Vegetation Policy: 1. Encourages a “stay away from steep slopes” mentality by placing additional vegetation replacement program. 2. Encourages preservation of existing established trees. 3. Offers property owner a menu of items allowing an array of vegetation types while encouraging the use of native species. 4. Defines anything above a thirty-three (33%) percent grade officially as a Steep Slope with a distance of at least 100 linear feet. 5. Allows for the possibility of a credit program for maintaining placement of mature trees and the protection of native trees. 6. Vegetation program allows for covering more ground per sq. ft. vs. number of trees methodology. 7. Policy creates a formula to provide flexibility and choice while maintaining a sq. ft. focus and tree conservation.
Allows the Land Development Office to review Landscape Plan submittals prior to the issuance of a Land Disturbing permit to review Steep Slope development plans before vegetation is removed to retain placement of mature trees, the protection of native trees, and the planting of new trees, which are considered for any credit on a Steep Slope as part of the Land Disturbance permit application process.
SECTION 4. BE IT FURTHER ORDAINED, that this Ordinance shall take effect on July 1, 2021 to allow staff, engineers, and land owners to adapt to these new vegetative requirements and this Ordinance shall further have a one (1) year review by the Council before July 1, 2022, to determine if any changes need to be made.