STAFF REPORT

STAFF REPORT
Planning and Zoning Board, August 15, 2005

Land Development Ordinance (LDO) (Round 5) (PL05-030c)
Consideration of a series of modifications and revisions to the Land Development Ordinance related to implementation of a Conservation Overlay District and modifications to riparian buffer regulations and nitrogen removal credits.

Speaker:
Don Belk, Senior Planner

From:
Jeffery G. Ulma, AICP, Director, Planning Department
Tim Bailey, Director, Engineering Department

Prepared by:
Angela Reincke, ASLA, Senior Planner, Planning Department
Don Belk, AICP, Senior Planner, Planning Department
Betsy Pearce, Stormwater Specialist, Engineering

Approved by: William B. Coleman, Jr., Town Manager
Approved by: Benjamin T. Shivar, Assistant Town Manager

BACKGROUND:

Staff has drafted environmental regulations related to various portions of the Land Development Ordinance text to be included in Round 5 of LDO amendments. Item 1 (see Proposed Round 5 Summary table) is the establishment of the Conservation Residential Overlay district, as recommended in the Southwest Area Plan. The proposed language for the overlay district ordinance was presented to the Town Council’s Planning and Development Committee on April 20 and was recommended for Public Hearing. The staff held a community information meeting on May 17 at the Green Level Baptist Church for property owners who would be affected by the Overlay. At this meeting, staff gathered feedback and explained the proposed overlay district and how it will be implemented. The general response from the residents was positive, although several citizens expressed concerns regarding minimum lot sizes in the Conservation Residential – Low Density area.

A public hearing before the Town Council was held on June 9. While generally supportive of the amendment to establish a Conservation Residential Overlay District, several citizens expressed concerns on specific points, including (1) the proposal to allow reductions in lot size for certain stream buffer-impaired parcels; (2) preserving land equity for generational landowners in the southwest area; (3) more precise definitions of priority open space; and (4) the definition of ‘low density residential’. One landowner opposed the amendment based on his continued opposition to the Southwest Area Plan, citing a perceived ‘taking’ from the split designation of property between low density and very low density.

Town Council members reiterated many of the citizens’ concerns. Specifically, Councilmember Robinson cited the need for better protection of roadside viewsheds, along with wider buffers around new subdivisions developed under these proposed regulations. Councilmember Dorrel stated that the amendment represented a fair and balanced approach, given that the density bonus provisions represented a ‘trade-off’ with the incentive of a fair economic return in exchange for preserving open space. Councilmember Robison inquired about examples or case studies of conservation subdivision designs. (Such examples of successful conservation subdivision design, such as those that could be developed under the standards of this proposed ordinance, can be found in the supplementary report of the Open Space and Historic Resources Plan, entitled Conservation Subdivision Design.)

Two letters from southwest area landowners in support of the ordinance were received during the week following the public hearing.

Following the public hearing, a work session was held with the Planning and Zoning Board on June 20.

CHANGES TO ITEM 1 (CONSERVATION RESIDENTIAL OVERLAY DISTRICT ORDINANCE) SINCE THE PUBLIC HEARING: In response to the input from Town Council, citizens, and landowners during the community involvement phase, public hearing, and work sessions, Staff proposes several changes to the proposed Conservation Residential Overlay District Ordinance, as summarized below:

§ Base Density Option: Conventional Subdivisions within the Conservation Residential Overlay District (Table 4.4.2) was changed. The Maximum Permitted Yield for Conservational Residential – Very Low Density was increased from 0.5 units/acre to 1.0 unit/acre in order to approximate the lot size and density (40,000 SF; approximately 1.0 unit/acre) permitted under the existing R-40 zoning.

§ Primary Open Space was re-categorized into three classes that clarify open space priorities under the Southwest Area Plan. Class I (streetscape), Class II (National Register Historic District primary contributing structure, American Tobacco Trail buffer), and Class III (upland forest contiguous to other primary open space, greenway corridors outside of jurisdictional stream buffers)

§ Density Bonuses for Preserved Open Space were changed to give greater weight to Class I and II Primary Open Space: 12 units/acre for Class I; 10 units/acre for Class II; 8 units/acre for Class III

§ Section 4.4.5(F)(3) was revised to stipulate that within the Conservation Residential Overlay District process is mandatory for developments utilizing the Density Bonus Option, which supersedes the cluster housing option in LDO Section 8.3.

§ Section 4.4.5(F) (7), Pedestrian Connectivity, was revised to make greenway and trail terminology consistent with the Parks, Greenways, and Cultural Resources Facilities Master Plan.

§ Note 1 of Table 4.4.2 and Table 4.4.3 was revised to clarify that a 50’ roadway setback is a requirement within the Conservation Residential Overlay District.

§ Note 2 of Table 4.4.2 was revised to prohibit use of the cluster housing option in LDO Section 8.3 so that the incentives of the Density Bonus Option are maintained.

§ Note 2 of Table 4.4.3 was revised to specify that LCR lots shall conform to R-8 standards, residential lots less than 8,000 SF shall conform to Transitional Residential District (TR) standards, and that VLCR and Rural lot dimensions shall conform to R-20 and R-40 standards, respectively.

§ Note 3 of Table 4.4.2 and Table 4.4.3 was revised to specify the requirements of the buffer along the American Tobacco Trail.

§ Note 3 of Table 4.4.3 was revised to provide a definition of ‘preservation’.

§ Subdistricts Created and Defined. A new subsection 4.4.5(C) was added to clarify Conservation Residential – Low Density (LCR), Conservation Residential – Very Low Density (VLCR), and Rural as subdistricts of the Overlay District.

One change not made relates to the issue of wider buffers around new subdivisions developed under the standards of this proposed ordinance. Staff believes that requiring such perimeter buffers is unnecessary and could actually hinder conservation subdivision design by leading to an ‘artificial’ configuration of “rings of open space” around the perimeter of a site. Such open space would be established using parcel or project boundaries – manmade features - rather than the contours and features of the natural landscape. Requiring such additional open space will compete with the ability to preserve meaningful, contiguous open space.

Brief Summary of Conservation Residential Overlay District Ordinance

The Conservation Residential Overlay District Ordinance will implement the recommendations of the Southwest Area Plan (SWAP). The ordinance establishes standards for lot sizes, road setbacks and maximum development density within the areas designated as Conservation Residential Low Density and Very Low Density in the SWAP. The Overlay District ordinance retains the underlying R-40 zoning. However, the ordinance contains density bonus provisions and open space preservation standards for obtaining increased density and reduced lot sizes. Key provisions of the Conservation Residential Overlay District ordinance, as amended above, include:

§ Maximum Allowable Gross Density of 2.5 units/acre in the Conservation Residential – Low Density (LCR) areas and 1.0 unit/acre in the Conservation Residential – Very Low Density (VLCR) areas per the SWAP;

§ Minimum lot size of 10,000 square feet in LCR and 20,000 square feet in VLCR; however, parcels within the LCR areas that are significantly affected by stream buffers (greater than 20% of gross acreage) may reduce lot sizes incrementally to achieve maximum allowable gross density;

§ Town stormwater requirements shall be met by using a combination of Low Impact Development techniques along with conventional treatments;

§ Use of the density bonus option requires the preservation of open space beyond the required streetscapes, perimeter buffers, and stream buffers, with roadside open space (expanded streetscapes), preservation of historic structures and landscapes in the Green Level Historic District, expanded buffers along the American Tobacco Trail, and preservation of upland hardwood forests the priorities for additional preserved open space;

§ Density Bonuses vary according the category of open space preserved, either Primary or Secondary. Primary Open Space consists of 3 priority classes, with 12 additional housing units for every acre of Primary Class I open space preserved, 10 units for every acre of Primary Class II, and 8 units per acre of Class III. Five (5) additional housings units are allotted for every acre of Secondary Open Space preserved.

§ Rezoning is not required for applications meeting the requirements of the ordinance.

In Item 2, the riparian buffer regulations are also recommended to be changed to ensure that parts of streams that temporarily go underground are buffered.

The summary table of all these amendments and other modifications is presented on the following page. The table includes the relevant LDO section being modified as well as the purpose for the proposed amendment. The proposed amendment wording is also attached.

Staff Recommendation: Staff recommends approval of the Land Development Ordinance Round 5 Amendments.

Proposed Round 5 Summary

Item #	Amendment Description	LDO Section	Purpose for Amendment
1	Adding the Conservation Residential Overlay District (see Fig. 1 below)	4.4.5	The proposed language will guide development in this area to meet the intent of the Southwest Area Plan.
2	Minor modification to the riparian buffer regulations	7.3.2	The proposed language clarifies conflict between field conditions and applicable maps and exemptions of exclusion of buffers from lots.
3	Add note to existing table	7.3.5 Table 7.3-3	Proposed note provides additional details to BMP nitrogen removal efficiency.
4	Add principle of interpretation for riparian buffer modification requirements	7.3.7 (A)	The proposed language will clarify the intent of the compensatory mitigation requirements for riparian buffer modifications.

Fig. 1 – Applicable Subdistricts of the Conservation Residential Overlay District Ordinance (see Table 4.4.1)

Conservation Overlay Rezoning Case 05-REZ-17

The Conservation Residential Overlay District is established to implement the goals and objectives established in the Southwest Area Land Use Plan.

The Conservation Residential Overlay District shall apply to the geographic areas designated as Conservation Residential in the Southwest Area Plan adopted by Town Council on August 12, 2004 , or as may be amended. The district boundaries may not necessarily correspond to the Southwest Area Plan boundary. The current boundaries of the district are shown on the Official Zoning Map. The Conservation Residential Overlay District ordinance does not apply to parcels that are located within Planned Developments and valid site plans approved prior to July 15, 2004.

Due to the existing character and desired types of future development in the southwest area, differing residential densities, dimensional standards, open space requirements, and other related development standards are spelled out in the Southwest Area Plan. In order to present the full range of zoning and development requirements for each different area, this overlay zoning district is divided into such subdistricts as delineated in the Southwest Area Plan as follows:

Rezoning is not required for applications meeting the requirements stated in 4.4.5(F) below.

All development within the Conservation Residential Overlay shall require submission of a subdivision plan or site plan in accordance with Section 3.9 of this Ordinance, and approval of such plan by the appropriate decision-making body.

(E) Requirements for Developments within the Conservation Residential Overlay District
(1) Base Density Option

Subdivisions within the Conservation Residential Overlay District may be approved as subdivisions per Section 3.9 provided they comply with the standards established by the Southwest Area Plan, as follows:

Subdivisions within the Conservation Residential Overlay District may increase their development yield by preserving open space and employing the incentive measures described in Section 4.4 of the Southwest Area Plan, Density Bonus Provisions to Encourage Preservation of Open Space, and explained in Section 4.4.5(F)(4) below.

For lands within the Conservation Residential Overlay District, the planning process set forth in this Section is mandatory for developments utilizing the Density Bonus Option outlined in Table 4.4.3 below and supersedes the Alternative Development Option: Cluster Housing described in Section 8.3.

Standards for subdivisions utilizing the Density Bonus option are shown as follows:

Use of the Density Bonus Option requires preserved open space beyond the required streetscapes, perimeter buffers, and stream buffers. The following standards apply to the additional open space preserved under the Density Bonus Option:

(a) Primary Open Space: The classes of Primary Open Space are listed as follows in order of priority:

Class II: (a) Primary contributing structure within the Green Level National Register Historic District shall count as 1 acre of Class II primary open space, provided that the structure is preserved and/or rehabilitated to the Secretary of the Interior’s Standards for Rehabilitation and when included within at least 1 acre of Class II open space to preserve additional rural character features.

Class III: (a) Upland forest (upland hardwood and mixed hardwood/conifer) that is contiguous to other Primary open space.

(b) Greenway corridors, outside of jurisdictional stream buffers, that are part of the Town’s greenway master plan.

The priority order of Primary Open Space may be altered when, at the discretion of the Planning Director, it is determined that preservation of specific resources is most important for meeting the goals and objectives of the Comprehensive Plan.

(b) Secondary Open Space: Includes all other additional preserved open space not contiguous to Primary Open Space; for example, non-contiguous upland hardwood or mixed hardwood forest, wetlands, or other land adjacent to existing stream buffers or perimeter buffers.

1. Twelve (12) additional housing units for every acre of Primary Class I Open Space preserved.

2. Ten (10) additional housing units for every acre of Primary Class II Open Space preserved.

3. Eight (8) additional housing units for every acre of Primary Class III Open Space preserved.

2. Five (5) additional housing units for every acre of Secondary Open Space preserved

Applicants shall demonstrate compliance with Open Space uses, ownership and maintenance standards in Section 8.3.5 and 8.3.6 of the Land Development Ordinance. All open space preserved under the Density Bonus Option shall be placed in common open space. Covenants or easements for additional open space preserved under the Density Bonus Option shall be recorded with the Wake County Register of Deeds. This recordation shall occur prior to or in conjunction with any required plats or the issuance of a certificate of occupancy. The Planning Director may approve the use of other protective agreements that will ensure no adverse impacts to preserved open space.

Subdivisions within the Conservation Residential Overlay District developed under Options (1) and (2) above may employ standards for Rural Collectors and Rural Thoroughfares as delineated in the Comprehensive Transportation Plan. Curb and gutter and sidewalks are not required for Rural Collectors and Rural Thoroughfares. Median curbs are permitted for Rural Thoroughfares, and the median may be landscaped with shrubs and bushes.

Greenways, instead of sidewalks, will be utilized to meet Town objectives of pedestrian connectivity. Sidewalks are not required along rural collectors and thoroughfares identified in Section 4.4.5.(F)(6) above.

New developments within the Conservation Residential sections will contain adequate greenways and secondary access trails to ensure connectivity to the public greenway system. Construction of primary greenway trails is required at the time of development. Secondary greenway trails, which will essentially function as sidewalks, are also required as development occurs. Primary and secondary greenways and other non-paved pedestrian connections will be constructed in accordance with the standards described in the Parks, Greenways, and Cultural Resources Facilities Master Plan.

(1) All perennial and intermittent streams, including lakes, ponds, and other bodies of water as indicated on the most recent version of the 1:20,000 scale (7.5 minutes) quadrangle topographic maps prepared by the United States Geological Survey (USGS) shall have a 100-foot-wide riparian buffer directly adjacent to such surface waters, excluding wetlands.

(2) All other surface waters as indicated by the most recent version of the Soil Survey of Wake or Chatham County , North Carolina , shall have a 50-foot-wide riparian buffer adjacent to such waters.

(3) In the Neuse River Basin , where obvious conflicts between actual field conditions and USGS and Wake County Soil Survey maps exist, appeals may be made to the North Carolina Division of Water Quality. All other appeals for obvious conflicts may be made to the Town Manager or his or her designee.

(4) Underground streams and hydrologically connected wetlands must be buffered where stream delineations indicate a stream exists upstream and downstream of the area where a stream has gone underground or entered wetlands. The area to be buffered will be based on staff’s interpretation of USGS and Soil Survey maps and best professional judgment based on a field evaluation.

(5)~~(4)~~ Appeals to the 100-foot wide riparian buffer may be made as allowed by Section 7.3.7.

Stream buffers shall be shown on all site plans and subdivision plats approved within the Town’s planning jurisdiction. In addition, riparian buffers and COE jurisdictional wetlands shall be shown on the inventory of natural resources required as part of site and/or subdivision plan approval.

Generally, no single-family lots created through a site and/or subdivision plan shall be platted into a riparian buffer. However, the Town Council may allow riparian buffers to be included in lots only when all of the following conditions are met:

~~(1)~~ ~~The buffer impacts a limited part of the subdivision (e.g., less than ten lots)~~the subdivision is limited in size and has no homeowners association;

(2) There is no other reason for the formation of a homeowners association (e.g., covenant, other common areas, engineered stormwater control structures);

(3) The buffer is placed in a permanent conservation or other legal instrument dedicated to the Town (required documents must be provided prior to recording the plat for the impacted area).

~~(4)~~ Buffers allowed to be included in lots under this section shall meet the requirements of Section 7.2.3 (J), Ownership of Buffers.

All requests for relief from the requirements of this Section, only as they apply to Zone 3 of a riparian buffer within the Neuse River Basin or any riparian buffer Zones within the Cape Fear River Basin , shall be decided by the Town Council. Relief from the requirements of this Section may also be permitted through the Planned Development District rezoning and/or site plan approval processes provided sufficient documentation is provided to meet criteria listed below. Banking land within the same watershed may be required. The land to be banked shall have significant water quality value, such as being contiguous to an existing flood plain, wetland, or riparian area. The land to be banked shall be preserved in a permanent conservation easement or other legal instrument whose provisions prohibit both farming and unapproved logging. This modification shall be based on documentation of practical difficulties or unnecessary hardships and documentation of the effects on water quality caused by development within the buffers as related to the following criteria. This documentation must include but not be limited to concept plan for the use of the site and data showing the impact on water quality

(1) The basic project purpose cannot be practically accomplished in a manner that would better minimize disturbance and protect water quality;

(2) The use cannot practically be reduced in size or density or redesigned to minimize disturbance and protect water quality;

(3) BMPs will be used if necessary to minimize disturbance and protect water quality;

(5) Compensatory mitigation must be done on at least a 1:1 ratio on a square foot basis for any impacts to the Zone 3 riparian buffer. Mitigation ratios will be determined on a case-by-case basis. Additional mitigation may be required based upon the severity of impacts. Suggested mitigation ratios are listed below: