The Regional Planning Agency staff, after an extensive study, is recommending tighter restrictions and building curbs for Chattanooga's steeps slopes and low-lying areas.
The RPA report is available on its website.
The City Council is having a public meeting on Nov. 5 at 6 p.m. to take comments on the report.
The City Council Planning and Zoning Committee will provide RPA staff with direction on how to proceed with the staff recommendations in the report at the Nov.
12 agenda meeting at 3 p.m.
The report says, "A lack of appropriate zoning regulation standards or other tools that are necessary to appropriately regulate development and construction activity occurring in natural resource areas has led to inconsistency in the rezoning process. While current regulations do address filling in the floodplain, they do not address excessive site clearing, grading or limiting development in natural resource areas. In some instances, current regulations (such as setbacks and right-of-way standards) can increase impacts to these sensitive sites.
"Without zoning standards, RPA staff is reacting to rezoning requests by creating conditions “on the fly” to provide protections of natural resources. The Land Development Office (LDO) has to track
conditions on the back end of development review as opposed to a codified regulation or development standard. This results in less predictability and consistency in defining appropriate site design and best management practices for development or construction activity in natural resource areas."
It also says, "The analysis indicates the City lacks certain standards or tools in the zoning or subdivision regulations that could be effective at addressing public concerns and issues and provides suggestions on how to alleviate the concerns based on best management practices from the peer review jurisdictions."
The report states: RPA’s recommendations are not intended to limit or prohibit growth and
development on steep slopes or floodplains. The recommended Natural Resource Ordinance is meant to provide standards that allow for the appropriate and wise development of sites containing slopes and floodplains.
"As noted earlier in this summary, 54% of the remaining vacant land is on steep slopes, and permit trends have indicated that development activities will continue to increase in these sensitive areas as the City grows.
"Currently Chattanooga only regulates two of twenty-two common zoning standards found among the six peer cities. The increase in citizen concerns and complaints about loss of tree cover, mass grading, stormwater run-off and impacts to the City’s scenic character has served as an indicator that the current standards for sensitive site development are inadequate. It is also important to note that many of the current standards actually make the problem worse by offering limited flexibility in
setbacks, right-of-way widths, and density incentives to promote protection of sensitive areas."
Recommendations include:
1. Definition of Steep Slope
Define a percentage grade of a “steep slope” that will serve as a baseline for the Natural Resources Ordinance. For illustration purposes only, slopes could be categorized as “Moderate Slopes: 15-25%” and “Very Steep Slopes: 25% or greater.”
2. Land Use Restrictions
Establish a special permit process for intensive land use activities (such as hospitals, public assembly uses, and intensive non-residential uses) that may occur in high hazard areas such as
documented slope hazard areas or flood-prone areas. The main objective is to ensure the use would not present accessibility issues or pose safety concerns for less mobile residents such as a nursing home.
3. Limitations on Clearing, Grading or Disturbance
Establish restrictions that limit the amount of clearing, grading, and disturbance permitted on a site during construction. For example, for sites with slopes of 15% to 25% the amount of disturbance permitted in the sloped area could be limited to no more than 50% clearing, grading, or disturbance. For sites with slopes of 25% or greater the amount of disturbance permitted in the sloped areas could be limited to no more than 25% of clearing, grading, or disturbance.
4. Tree Canopy Protection Standards
Explore options of requiring a certain percentage of existing tree canopy on the development site to be retained and protected during construction for sensitive natural resource sites. Existing tree canopy retained could be used as credits towards any open space or landscape yard requirements.
5. Limit Amount of Impervious Surface
Establish standards or regulations limiting or reducing the amount of impervious surfaces for non–residential uses such as minimizing parking space stall dimensions, required number of compact car stalls, using porous surfaces, encourage shared parking, and encourage structured parking decks.
For residential uses limiting the amount of driveway and building footprint to a certain percentage of the total lot area.
6. Establish a “Zero Net Increase” in Floodplain Fill
Establish standards that require compensatory storage to off-set fill. This is often referred to as a 1:1 fill ratio. The basic concept is an equal volume of fill shall be removed for a site to compensate for the same volume of fill that is placed in the floodplain.
7. Density Bonus
Establish a density bonus in residential density if a certain percentage of a site or lots with natural resources is preserved and set aside from development. For example, Asheville, North Carolina permits a residential density bonus of 30% if 30% to 40% of the site with natural resources is preserved. The density bonus increases as the amount of land preserved increases up to a maximum of a 60% density bonus.
For non-residential uses the density bonus could be an increase in building height or reduced parking requirements.
8. Flexibility in Required Setbacks
Establish a staff approval process for reductions in front and rear setbacks if a portion of the site containing natural resources is preserved and site grading is limited.
9. Lots of Record
Existing lots legally recorded prior to the adoption of the Natural Resources Ordinance should be analyzed more thoroughly to determine their requirements of the Natural Resource Ordinance and
if there would be any unintended consequences or undue hardship created for lots of records by being required to comply with the Natural Resources Ordinance. However, lots of record could be eligible for reduced setbacks if the natural resource area on the site is preserved and no grading occurs in this area. Special standards could be developed that factor in different home construction techniques (such as slab construction versus pier construction). Additional flexibility will be needed to address the unique site conditions for each lot of record.
The overall objective is to establish some basic parameters on clearing and grading on a lot of record.
10. Planned Unit Development (PUD)
Amend the PUD tool with new and up-to-date standards and criteria that can be used as a tool to protect natural resource areas and provide incentives for developers such as an increase in the permitted density in exchange for preserving sensitive areas or providing useable open space for residents.
OTHER RECOMMENDED TOOLS
As part of this assessment RPA determined that other regulations or tools will need to be amended or created and are briefly described below.
City of Chattanooga Subdivision Regulations
RPA is recommending amendments to the Chattanooga Subdivision Regulations as additional tools of protection of our scenic assets and natural amenities.
1. Road Reductions on Hillsides
Allow an opportunity in the subdivision regulations to reduce the required minimum right-of-way in hillsides or sloped areas to reduce the amount of impervious surface and land clearing necessary for the construction of streets. This will require coordination and discussions with other partners such as Chattanooga Department of Transportation (CDOT) and the Fire Marshal’s Office.
2. Critical Lot
Lots that contain steep slopes, soil conditions/high erodibility, and floodplains should be identified on the subdivision plat as a critical lot and should be evaluated by a geotechnical engineer/report as to the feasibility of construction and methods of construction that will address the stabilization and stormwater run-off associated with a critical lot.
3. Slope Map
Staff is recommending that slope maps be provided by applicants during permit review showing the delineation of existing slope categories. Slope maps are available through a free website from
Hamilton County GIS.
4. Site Assessment Map
Staff is recommending a site assessment map be provided by applicants during permit review that shows the approximate location and indication of size and condition of all natural hazards and sensitive environmental features found within boundaries of the proposed subdivision. Such items include sinkholes, soil classifications, springs, wetlands, bluffs, streams, etc.
5. Conservation Based Design Subdivision Standards
Create a conservation based design subdivision tool that provides clear standards for natural resource protection. This tool will establish regulations that require a certain percentage of the area to be permanently protected as open space. In return the developer is provided with flexibility in required minimum lot size, setbacks, lot frontage, and street widths. Density bonuses could also be part of the requirements for conservation based design subdivisions.
6. R-1 Open Space Option
The R-1 Open Space Option was adopted by City Council in 1995 and has rarely been utilized. This tool should be evaluated to determine why it is not being used and if possible amendments are required.
This option may need to be removed from the Chattanooga Zoning Regulations as this is not a zoning classification; it is a subdivision design option that provides alternative design standards for
development of a single-family residential subdivision.
7. Promote more opportunities for infill development in less sensitive areas
RPA is in the process of creating areas plans for the City of Chattanooga. One goal or policy of the area plans is to encourage infill development in established neighborhoods and supports various
housing forms and types to meet the housing demand and opportunities to provide affordable housing for the residents of Chattanooga. Opportunities to promote more housing infill options
should be identified and established with each area plan.
Improvements to Permitting Process/Code
Based on the peer view, Gaps Analysis, and best management practices from city staff and stakeholders, there may be additional opportunities for the Land Development Office to explore options for possible amendments to Municipal Code Section 31, Stormwater Management to address concerns and issues voiced by the public. RPA has contacted the Land Development Office, and they are aware of these recommendations and are supportive of the following:
1. Landscaping and Material Facing of Retaining Walls
Explore options of requiring landscaping or material facing for landscape retaining walls of a certain size.
2. Timing of Retaining Wall Construction
Explore options of requiring that retaining walls be constructed onsite prior to the start of construction of the building or structure.
3. Limitations on the Amount of Land Disturbance of Grading Permitted at One Time
Explore options of limiting the amount of clearing, grading, or disturbance permitted at any one time on a site. For example, a maximum of 10 acres of clearing, grading, and disturbance should be
permitted only with the 10 acres being stabilized and revegetated prior to applying for additional clearing, grading, or disturbance for other areas on the same development site.
4. Security Bond for Revegetation/Stabilization
Explore options of requiring a security bond or letter of credit for sites of a certain size to provide the city required revegetation and stabilization.
5. Slope Stability Certifications
Explore option of requiring a geo-technical engineering report or certificate for slopes sites that the site or slope is free of failures, and that temporary or permanent ground cover is provided.
6. Site Plan Review or Geo-Technical Report for Critical Lots
Explore option of requiring detailed site plans for lots identified as critical lots. A critical lot would be a lot with slopes, floodplains, and high soil erodibility. Additional measures should be required by
applicants such as a geotechnical engineer/report as to the feasibilityof construction and methods of construction that will address the stabilization and stormwater run-off associated with a critical lot.
7. Timing of Land Disturbing Permit and Start of Construction
Explore options of requiring that the start or beginning of building construction be noted on the application for a land disturbing permit, and the beginning of building construction to begin within so many days after permanent clearing, grading, and disturbance has ended.
The executive summary and report are available to download as a PDF.