(1) DEFINITION. In
this section, "protective area" means an area of land that commences at the top
of the channel of lakes, streams and rivers, or at the delineated boundary of
wetlands, and that is the greatest of the following widths, as measured
horizontally from the top of the channel or delineated wetland boundary to the
closest impervious surface. However, in this section, "protective area" does
not include any area of land adjacent to any stream enclosed within a pipe or
culvert, so that runoff cannot enter the enclosure at this location.
(a) For outstanding resource waters and
exceptional resource waters, 75 feet.
(b) For perennial and intermittent streams
identified on a U.S. geological survey 7.5-minute series topographic map, or a
county soil survey map, whichever is more current, 50 feet.
(c) For lakes, 50 feet.
(d) For wetlands not subject to par. (e) or
(f), 50 feet.
(e) For highly
susceptible wetlands, 75 feet. Highly susceptible wetlands include the
following types: calcareous fens, sedge meadows, open and coniferous bogs, low
prairies, coniferous swamps, lowland hardwood swamps, and ephemeral ponds.
Note: Information on wetland types, including ephemeral
ponds, is available at (608) 266-7012.
(f) For less susceptible wetlands, 10 percent
of the average wetland width, but no less than 10 feet nor more than 30 feet.
Less susceptible wetlands include: degraded wetlands dominated by invasive
species such as reed canary grass; cultivated hydric soils; and any gravel
pits, or dredged material or fill material disposal sites that take on the
attributes of a wetland.
(g) In
pars. (d) to (f), determinations of the extent of the protective area adjacent
to wetlands shall be made on the basis of the sensitivity and runoff
susceptibility of the wetland in accordance with the standards and criteria in
s.
NR 103.03.
(h) Wetland boundary delineation shall be
made in accordance with s.
NR 103.08(1m). This paragraph does not
apply to wetlands that have been completely filled in compliance with all
applicable state and federal regulations. The protective area for wetlands that
have been partially filled in compliance with all applicable state and federal
regulations shall be measured from the wetland boundary delineation after fill
has been placed. Where there is a legally authorized wetland fill, the
protective area standard need not be met in that location.
(i) For concentrated flow channels with
drainage areas greater than 130 acres, 10 feet.
(j) Notwithstanding pars.(a) to (i), the
greatest protective area width shall apply where rivers, streams, lakes, and
wetlands are contiguous.
Note: A stream or lake is not eligible for a lower
protective area width even if contiguous to a less susceptible wetland.
(2) APPLICABILITY. This
section applies to post-construction sites located within a protective area,
except those areas exempted pursuant to sub. (4).
(3) REQUIREMENTS. The following requirements
shall be met:
(a) Impervious surfaces shall be
kept out of the protective area entirely or to the maximum extent practicable.
If there is no practical alternative to locating an impervious surface in the
protective area, the storm water management plan shall contain a written,
site-specific explanation.
(b)
Where land disturbing construction activity occurs within a protective area,
adequate sod or self-sustaining vegetative cover of 70 percent or greater shall
be established and maintained where no impervious surface is present. The
adequate sod or self-sustaining vegetative cover shall be sufficient to provide
for bank stability, maintenance of fish habitat, and filtering of pollutants
from upslope overland flow areas under sheet flow conditions. Non-vegetative
materials, such as rock riprap, may be employed on the bank as necessary to
prevent erosion such as on steep slopes or where high velocity flows occur.
Note: It is recommended that seeding of non-invasive
vegetative cover be used in the protective areas. Some invasive plants are
listed in ch. NR 40. Vegetation that is flood and drought tolerant and can
provide long-term bank stability because of an extensive root system is
preferable. Vegetative cover may be measured using the line transect method
described in the University of Wisconsin extension publication number A3533,
titled "Estimating Residue Using the Line Transect Method".
(c) Best management practices such as filter
strips, swales, or wet detention ponds, that are designed to control pollutants
from non-point sources, may be located in the protective area.
Note: Other laws, such as ch. 30, Stats., and chs.
NR 103,
115,
116, and 117 and their associated
review and approval processes may apply in the protective area.
(4) EXEMPTIONS. This
section does not apply to any of the following:
(a) Except as provided under s.
NR 151.121(5), redevelopment
post-construction sites.
(b)
In-fill development areas less than 5 acres.
(c) Structures that cross or access surface
waters such as boat landings, bridges, and culverts.
(d) Structures constructed in accordance with
s.
59.692(1v),
Stats.
(e) Areas of
post-construction sites from which the runoff does not enter the surface water,
including wetlands, without first being treated by a BMP to meet the
requirements of ss.
NR 151.122 to 151.123, except to the extent that
vegetative ground cover is necessary to maintain bank stability.
A vegetated protective area to filter runoff pollutants
from post-construction sites described in par. (e) is not necessary since the
runoff at that location is treated prior to entering the surface water. Other
practices necessary to meet the requirements of this section, such as a swale
or pond, will need to be designed and implemented to reduce runoff pollutants
prior to runoff entering a surface water of the state. The requirements of ch.
NR 103 still apply and should be considered before runoff is diverted to or
from a wetland.
