§ 88-415-07. ADDITIONAL STANDARDS

The following additional standards apply within stream buffers.

88-415-07-A. CONTINUOUS VEGETATION

When existing vegetation within stream buffers is disturbed, required buffers must be revegetated with appropriate native riparian vegetation.

88-415-07-B. STORMWATER DISCHARGE

Direct stormwater discharge into stream channels is allowed only in accordance with the city's Standards, Specifications, and Design Criteria.

88-415-07-C. MITIGATION

1.

Property owners who elect to establish the maximum outer zone width in accordance with 88-415-03-C.2 may exceed the 40% disturbance limit established in 88-415-05-C.2(a) by an additional 10%, up to 50%. This additional disturbance is allowed if an equal or greater land area is added to the outer zone to mitigate the additional allowed (10%) disturbance and if the applicant mitigates the impacts by maintaining natural resource functions, including base flood elevations and stream stability and geomorphology, and by replacing existing mature riparian vegetation with an equivalent amount of appropriate native riparian vegetation.

2.

Mitigation areas become part of the property's permanent open space and must be:

a.

contiguous to the original outer zone;

b.

permanently stabilized where slopes greater than 15% are present;

c.

revegetated in accordance with 88-415-07-A;

d.

established and maintained in accordance with the provisions of this article and Article 88-410;

e.

designed, established, and maintained in accordance with the city's Standards, Specifications and Design Criteria and applicable state and federal laws and regulations; and

f.

completed during the development phase in which disturbance occurs, if applicable.

g.

additional mitigation requirements are found in 88-415-08-B.4. (a) through (g).

3.

The mitigation standards of this section also apply whenever an exception to stream buffer standards is approved.

88-415-07-D. BUFFER PLAN

1.

A stream buffer plan must be provided when the stream buffer standards apply. The plan must delineate the buffer zones and the proposed development site in relation to:

(a)

the FEMA- or city-designated floodplain or the estimated 1% flood conveyance, as determined by a qualified engineer using city-approved methods;

(b)

wetlands within or adjacent to the floodplain or required stream buffer;

(c)

slopes in excess of 15% within or adjacent to the floodplain, as field-surveyed; and

(d)

mature riparian vegetation, including woodlands, wetlands, and other habitat areas identified by a field survey.

2.

A preliminary buffer plan must be submitted for city review with preliminary plats and site or development plans. The preliminary buffer plan must include a plan at a scale no smaller than 1" = 100' showing at a minimum:

(a)

existing topography with at least 2-foot contour intervals;

(b)

approximate stream locations based on approved city geographic information system mapping or city-approved mapping from state and federal agencies;

(c)

approximate boundary of the FEMA- or city-designated floodplain based on city-approved geographic information system mapping or federal mapping;

(d)

approximate 1% flood conveyance limits where no regulatory floodplain is identified as determined by a qualified engineer using city-approved methods;

(e)

approximate wetland locations from the Mid-America Regional Council Natural Resource Inventory, or the U.S. Fish and Wildlife Service National Wetlands Inventory;

(f)

approximate boundary of existing, mature riparian vegetation based on a field survey;

(g)

slopes of 15% or greater in each sub-drainage area based on city-approved geographic information system mapping or a site topographic survey;

(h)

the location of proposed structures or activities;

(i)

identification of required stream buffer zones based on city-approved geographic information system mapping or a site topographic survey and a survey of mature riparian vegetation;

(j)

the total acreage of mature riparian vegetation and steep slopes in the outer zone;

(k)

the location and total acreage of proposed clearing and grading in the outer zone and the percentage of proposed outer zone area to be cleared (if applicable in accordance with 88-415-03-C88-415-03-C; and

(l)

the limits and total acreage of proposed mitigation of outer zone vegetation, and the percentage of outer zone area to be mitigated (if applicable in accordance with 88-415-07-C).

3.

The final buffer plan must be submitted for city review with or be included in final plats and site or development plans. The final buffer plan must include a plan at a scale not smaller than 1" = 100' showing at a minimum:

(a)

existing topography with at least 2-foot contour intervals;

(b)

field delineated, marked, and surveyed streams and wetlands;

(c)

field delineated, marked, and surveyed mature riparian vegetation limits as described in 88-415-07-D.4;

(d)

existing sub-drainage areas of the site;

(e)

slopes of 15% or greater in each sub-drainage area based on a site topographic survey;

(f)

the location of proposed structures or activities;

(g)

the location of field delineated and surveyed stream buffer zones;

(h)

the total acreage of mature riparian vegetation and steep slopes in the outer zone;

(i)

the location and total acreage of proposed clearing and grading in the outer zone, and the percentage of proposed outer zone area to be cleared (if applicable in accordance with 88-415-03-C88-415-03-C; and

(j)

the limits and total acreage of proposed mitigation of outer zone vegetation and the percentage of outer zone area to be mitigated (if applicable in accordance with 88-415-07-C).

4.

Field surveys of mature riparian vegetation must identify the limits of the mature riparian vegetation for inclusion with the preliminary and final buffer plans, to a maximum of 250 feet from the edge of the middle zone or 150 feet from the edge of the middle zone at the property owner's election pursuant to 88-415-03-C88-415-03-C. At a minimum, a licensed surveyor, professional engineer, or landscape architect must delineate the existing edge of the tree canopy. The survey must identify the critical root zone of all trees at the mapped canopy cover boundary with a diameter breast height (DBH) of 10 inches or greater. The surveyor may identify specific tree species to more accurately delineate the riparian vegetation boundary if the mature vegetation appears to extend into uplands. The riparian boundary is assumed to exist when less than 50% of the mature trees (10-inch DBH or greater) are of riparian or bottomland species as defined by The Terrestrial Natural Communities of Missouri (Nelson 2006) and approved by the city. The surveyor must delineate the canopy cover boundary of the mature riparian tree specimens.

88-415-07-E. BOUNDARY MARKERS

1.

Boundary markers must be put in place clearly marking required stream buffers before, during, and after construction.

2.

Boundary markers must be installed at the intersection of private lot lines with the outer edge of the permanent open space before receiving final city approval of plans for clearing, grading, or sediment and erosion control.

3.

Construction fencing must be placed at the outer edge of the permanent open space in the outer zone to delineate the buffer. This fencing must be maintained throughout the construction process.

4.

Permanent signs must be placed at the edge of the permanent open space after construction to denote the buffer as follows:

(a)

For single-lot developments, signs must be posted every 100 feet along the boundary of the permanent open space.

(b)

For multiple lots located along a buffer, signs must be located at the intersection of every other lot line along the boundary of the permanent open space.

5.

Required signs must read: "Protected Stream Buffer - Do Not Disturb (City Code Section 88-415)," with the sign message located approximately 4 feet above the ground. Signs must be maintained and remain legible at all times.

(Ord. No. 120783, § 1, 10-4-2012)