City of Weldon Spring, MO Resource Conservation Planning And Design For All Subdivisions

[Ord. No. 18-12, 12-11-2018]

All subdivisions within the City shall avoid or minimize adverse impacts on the City's natural, cultural and historic resources as defined below.

Ground Water Resources.

The City's limited ground water resources shall be protected in order to ensure the provision of an adequate water supply to City residents and businesses as well as to protect the flow of the City's surface waters.

All subdivisions shall be designed to cause the least amount of disturbance to natural infiltration and percolation of precipitation to the ground water table.

This shall be accomplished through carefully planning land disturbance activities, through the use of vegetation and by not placing streets, buildings and other impervious surfaces in locations that have been identified on the site's existing resources and site analysis map that have been identified as areas having the greatest permeability where precipitation is most likely to infiltrate and recharge the ground water.

Stream Valleys, Swales, Springs And Other Lowland Areas. Stream valleys (which include stream channels and floodplains), swales, springs and other lowland areas are resources that warrant restrictive land use controls because of flooding hazards to human life and property, their ground water recharge functions, their importance to water quality and the health of aquatic communities and their wildlife habitats. They are generally poorly suited for on-site subsurface sewage disposal systems.

The following activities shall be minimized:

(1)

Disturbance to streams and drainage swales.

(2)

Disturbance to year-round wetlands, areas with seasonally high water tables and areas of surface water concentration.

(3)

Because of their extreme limitations, stream valleys, swales and other lowland areas warrant designation as open space or greenway lands. They may also require adjoining buffer lands to be included in the opens space/greenway as determined by an analysis of the protection requirements of such areas on a case-by-case basis. In certain instances, seasonal high water table soils may be excluded from the open space/greenway where it can be demonstrated that they are suitable for low density residential uses and conventional on-site sewage systems.

Woodlands. Woodlands occur throughout the City, often in association with stream valleys and wet areas, poor and erodible agricultural soils and moderate to steep slopes.

Woodland conditions within the City vary with respect to species composition, age, size and health. They range from relatively recent post-agricultural young stands to mature mixed-age forests. Most woodlands in the City represent one (1) or more of the following resource values:

(1)

As soil stabilizers, particularly on moderate to steep slopes, thereby controlling erosion into nearby streams, ponds, lakes, retention ponds and roads. A closely related function is their enhancement of recharging the water table.

(2)

As habitats for woodland birds, mammals and other wildlife.

(3)

As a means of improving harsh microclimatic conditions in both summer and winter.

(4)

As recreation resources for walkers, equestrians, hikers and other related outdoor activities.

(5)

As visual buffers between areas of development and adjacent roads and properties.

Because of their resource values, all woodlands on any tract proposed for subdivision or land development shall be evaluated by the applicant to determine the extent to which such woodlands should be designated partly or entirely as open space or greenway lands. Evaluation criteria shall include:

(1)

Configuration and size.

(2)

Present conditions (i.e., size, health and species composition).

(3)

Site potential (i.e., the site's capabilities to support woodlands based on its topographic, soil and hydrologic characteristics).

(4)

Ecological functions (i.e., in protecting steep slopes and erodible soils, maintaining stream quality and providing for wildlife habitats).

(5)

Relationship to woodlands on adjoining and nearby properties and the potential for maintaining continuous woodland areas.

The evaluation of the tract's woodlands shall be undertaken by a forester, landscape architect, horticulturist or other qualified professional.

In designing a subdivision and land development plan for any tract, the applicant shall be guided by the following standards:

(1)

Healthy woodlands exceeding one (1) acre should be preserved and designated as open space or greenway lands to the maximum extent possible.

(2)

Proposed site improvements shall be located, designed and constructed to minimize the loss or degradation of woodland areas.

(3)

Subdivisions shall be designed to preserve woodlands along roadways, property lines and linear features occurring within a site such as streams, swales, stone fences and hedgerows. Such linear features and the native vegetation associated with them should be preserved as buffers between adjacent properties and between areas being subdivided within a property. Preservation shall include ground, shrub, understory and canopy vegetation. Disturbance or removal of woodlands occupying environmentally sensitive areas shall be undertaken only when approved by the Board of Aldermen and on a limited, selective basis to minimize the adverse impacts of such actions. This shall, include, but not necessarily be limited to, vegetation performing important soil stabilizing functions on wet soils, stream banks and sloping lands.

(4)

No clearing or earth disturbance (except for soil analysis for proposed sewage disposal systems) shall be permitted on a site before the completion of subdivision and land development agreements. The determination of sight distance clearances along roadways shall be presented graphically.

Upland Rural Areas. These areas comprise fields, pastures, meadows and former agricultural areas in early stages of woodlands succession. These constitute the City's historic working landscape which may be dotted with historic houses, barns and other structures. They contribute to the City's rural character and because of their openness and potential high visibility and development in these areas is likely to be. These areas can provide habitat for wildlife in conjunction with nearby woodlands and stream valleys. The preferred location of development in the areas, if any, is the non-prime agricultural soils and lower topographic settings where development will be visually less obtrusive. Compact clustered residential designs, with coordinated architectural and landscape architectural themes, are encouraged in highly visible locations where future development cannot be avoided (such as at the far edge of open fields).

Slopes. Moderately sloping lands (fifteen percent (15%) to twenty-five percent (25%)) and steeply sloping lands (over twenty-five percent (25%)) are prone to severe erosion if disturbed. Erosion and the resulting overland flow of soil sediments into streams, ponds and public roads are detrimental to water quality and aquatic life and constitute a potential hazard to public safety. Areas of steep slope shall be preserved as required below.

All grading and earthmoving on slopes exceeding fifteen percent (15%) from surrounding ground shall be minimized.

No site disturbance shall be allowed on slopes exceeding twenty-five percent (25%), except grading for a portion of a driveway accessing a single-family dwelling when it can be demonstrated that no other routing that avoids slopes exceeding twenty-five percent (25%) is feasible.

On slopes of fifteen percent (15%) to twenty-five percent (25%), the only permitted grading beyond that described above shall be in conjunction with a single-family dwelling, its driveway and the septic system, if any (which should typically be designed with a long, narrow drainage field following the land contours).

Grading or earthmoving on all sloping lands of fifteen percent (15%) or greater shall not result in earth cuts or fills whose highest vertical dimension exceeds six (6) feet, except in the event that the City Engineer determines that no reasonable alternatives exist for construction of roads, drainage structures and other public improvements. If such a determination is made, vertical dimensions shall not exceed twelve (12) feet. Roads and driveways shall follow the line of existing topography to minimize the required cut and fill. Finished slopes of all cuts and fills shall minimize disturbance of natural grades.

Significant Natural Areas And Features. Natural areas containing rare, threatened or endangered plants and animals, as well as other features of natural significance, exist throughout the City. Some of these areas have been carefully documented by the Missouri Department of Conservation (MDC) in their natural heritage data. The applicant shall contact the MDC to determine what data they have for the site. Subdivision applicants shall take all reasonable measures to protect significant natural areas and features either identified by the City's map of potential conservation areas (Figure 3 in the Comprehensive Plan) or by the applicant's existing resources and site analysis map (as required in Section 410.230(B)(2) of these regulations) by incorporating them into proposed greenway areas or avoiding their disturbance in areas proposed for development.

Historic Structures And Sites. All subdivisions shall be designed to protect existing historic resources. The protection of an existing historic resource shall include the conservation of the landscape immediately around and associated with and significant to that resource to preserve its historic context. Where, in the opinion of the Board of Aldermen, a plat will have an impact on a historic resource, the developer shall mitigate that impact to the satisfaction of the Board of Aldermen by modifying the design, relocating proposed lot lines, providing landscape buffers or using other approved means.

Scenic Rural Road Corridors And Scenic Views. All subdivisions shall attempt to preserve scenic visual corridors along City roads and scenic views in the City by incorporating them into open space or greenway areas or providing building setbacks and/or architectural designs that minimize the subdivision's impact on said corridors and views. In instances when setbacks and/or design fail to satisfactorily protect corridors or views, the applicant shall be required to provide naturalistic landscape buffers to minimize their adverse visual impact. The species designated for said buffer shall be selected on the basis of tree and shrub species found in existing vegetated and wooded roadside edges in the vicinity of the proposed development.

Trails.

Trails shall be protected by permanent conservation easements. The width of the protected area in which the trail is located should be a minimum of ten (10) feet. The language of the conservation easement shall be to the satisfaction of the Board of Aldermen upon recommendation from the Planning and Zoning Commission.

The land area permanently designated for trails for public use may be credited toward the parks, playgrounds and recreation areas requirement described in Section 410.630 of the Subdivision Regulations.

Trail improvements shall demonstrate adherence to principles of quality trail design.

Trails shall have a vertical clearance of no less than ten (10) feet.

Width of the trail surface may vary depending upon type of use to be accommodated but in no case shall be less than three (3) feet or greater than six (6) feet.

No trail shall be designed with the intent to accommodate motorized vehicles.

When a proposed subdivision will traverse or abut an existing trail (either pedestrian, bike or equestrians), the Board of Aldermen may allow the applicant to alter the course of the trail within the proposed subdivision as long as the points at which the trail enters and exits the tract remain unchanged.

The proposed alteration does not coincide with a paved road intended for use by motorized vehicles.