HomeMy WebLinkAboutSpecial Report (009) LISA PALAZZi
~ -- c:~ 203 FOURTH AVENUE EAST SUlFa 32l
, ~~, ~ ~~.~llF. OLYMPIA, WASHINGTON 98501
~~ ~ VO,CE: (360) 534-0346
F^x: (360) 534-9027
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Joe Pollack
DEPT. OF COMMUNITY DEVELOPMENT
310 Disney Road ' .... · ........
Nordland, WA 98358
August 8, 1995
Report File Number: M95-0010
Report Subject: Wetland delineation report
Location: Approx. 60 acre site located west of Discovery Road, about 2
miles southwest of Port Townsend in Jefferson County; Portions of
the site are in Sections 20 and 29, Township 30N, Range 1W.
Field work was carried out by Lisa Palazzi, (ARCPACS certified soils specialist and wetlands
specialist) on several days over a several month period, including August 3, 16, September 8,
and October 5 1994. Wetlands were delineated and flagged in the field. Data was collected to
determine wetland rating.
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GENERAL REGULATORY FRAMEWORK
To qualify as a jurisdictional wetland, as defined by the federal 1987 Corps of Engineers
Manual (required by the Jefferson County Interim Critical Areas Ordinance), an area must
predominantly support wetland vegetation, must have hydric soils, and must have wetland
hydrology characteristics defined for the on site soil type -- in this case, evidence or observation
of a long-duration water table at 12 inches or less depth. In Jefferson County, the jurisdictional
wetland will only be regulated by the County if it is greater than 10,000 sq ft in size (personal
communication from Jefferson County personnel). The Wetland edge is located by evaluating
the presence or absence of the three parameters, then flagged in the field for subsequent survey.
Once identified as jurisdictional wetland, the wetland is "rated" using the October 1991
Washington State Wetlands Rating System (required by the Jefferson County Interim Critical
Areas Ordinance). The rating system combines a series of questions and a point system to
determine the specific value of the individual wetland. Depending on site specific, pre-
development wetland vegetatiOn, soils, hydrology and buffer characteristics, the wetland has
greater or lesser value and so is afforded varying levels of protection in the form of wetland
buffers (relative widths defined in the Ordinance). The higher the rating, the greater the buffer,
ranging from a minimum of 25 feet for relatively Iow quality, smaller wetlands adjacent to low
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intensity development areas (density ofless than I unit per acre) up to a maximum of 150 feet
for the highest quality, or rare wetlands adjacent to high intensity development areas (density
greater than I unit per acre).
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The area within the wetland and buffers is generally considered unavailable for development,
unless there is no reasonable alternative. Any impacts to the wetland are regulated at least by
Jefferson County and the federal Army Corps ofEngineers (COE). Other potentially involved
agencies include the state Dept. offish and Wildlife (WDFW), and the DNR Natural Heritage
Program. In general, any impacts must be mitigated for through either wetland creation or
enhancement program with the intent being no net loss of wetland acreage.
Impacts within the buffer are regulated only by Jefferson County, although the WDFW can also
become involved with setting buffer requirements.
OVERVIEW
Attached maps include:
1) a 1"=100' scale 1990 aerial photo of the site (source: DNR Aerial Photo and Map Sales,
Olympia WA);
2) an aerial topography map with preliminary wetland edges from earlier work (Source:
client)
3) On-site soil maps (source: Jefferson County SCS Soil Survey, issued in 1972 from work
done on a photo base dated 1951 and 1954)
;
Attached Appendices include: 1) A summary of the soil series descriptions
2) Wetland rating forms
Approximate wetland boundaries are marked on the aerial photo. Those boundaries are flagged
in the field. Some portion (possibly all) of that flagged edge has been Surveyed, but we have not
reviewed the results of that survey so cannot provide it herein. The survey map will supplant the
hand-drawn, estimated wetland edge map on the attached aerial photo for purpose of planning
and buffer setbacks.
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Geomorphology and Soils
The site is characterized by having a broad flat swale across its eastem majority with mild slopes
to southwestern and western uplands and some smaller areas of eastern uplands. The swale
drains from north to south with the wetland broadest at the northern end, then narrowing to a
small stream channel with a narrow wetland riparian zone in the southern portions.
There is a drain that runs across the wetlands from noah to south, generally trending toward the
western side of the wetland. Based on topography and local history, it is likely that the ditch is
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man-made -- that some portions of the original meander channel was ditched to improve
drainage at some time in the past. However, soil characteristics indicate that overall, the area
currently mapped as wetland is very close to what was originally wetland, probably due to a
combination of fine textured subsoils not draining effectively and due to the very moderate slope
of the drain.
According to the Jefferson County soil surveY, the following soil series are mapped on or near
the site: the Belfast silty clay loam and the Belfast silt loam, wet variant, (both classified as
coarse-loamy, mixed, non-acid, mesic Typic Udifluvent~); the Casey silt loam, 0-8% slopes
(classified as a fine, mixed, mesic Typic Albaqualfs2; the Clallam gravelly sandy loam, 0-15%
slopes (classified as a loamy-skeletal, mixed, mesic Entic Durochrept3) the Dick loamy sand, 0-
15% slopes (classified as a mixed, mesic Alfic Xeropsamment4); the Hoypus gravelly loamy
sand, 0-15% slopes (classified as a sandy-skeletal, mixed, mesic Typic XerorthentS); and the
Semiahoo muck and its moderately shallow variant (both classified as euic, mesic Typic
Medisaprists6).
The Belfast and Semiahoo soils are mapped across the wetland areas in the midsite swale with
the Belfast in the more channelized southern portions and the Semiahoo in the broader, northern
! Come-loamy, mixed, non-acid, mesic Typic Udifluvent generally meaning the soil is very young with minimal horizon
development (ent), is a result of periodic flooding activin' (fluv), has a Udic moisture regime -- in most years the soil between 4 and
12 inches depth not dry for more than 90 days (udi), has otherwise average characteristics for these soil types (~'pic), has a me. sic
temperature regime (mean annual temperature ranges from 8° to 15° C (47° - 59° F), has a Ph greater than 5.0 (non-acid), has no
specific mineralogical source (mixed), has > 15% sand content and <18% clay content by dry weight (coarse-loam.v).
2 Fine, mixed, mesic Typic Albaqualfs, generally meaning the soil has an argillic (clay) horizon and has greater than
35% base saturation (aiD, is expected to have a seasonal high water table within approx. 12 inches of the soil surface (aqu), has an
abrupt textural change betwecn the argillic (clays) B horizon and the overlying albic or ochric horizon (alb), is otherwise typical
(typic), has a mesic temperature regime (mean annual temperature ranges from 8° to 15° C (47° - 59° F), no specific mineralogic
source (mixed), and has 35-50% clay content (fmc).
.
3 Loamy-skeletal, mixed, mesic Entic Durochrept, generally meaning the soil has minimal horizon development (ept and
entic), has a pale-colored, low base saturation surface horizon (ochr), has an silicate-cemented subsurface laver (dm'), has a mesic
temperature regime (mean annual temperature ranges from 8° to 15° C (47° - 59° F), has no specific rnineralogic source (mixed),
textm'e of the fine fraction is loam and coarse fragment content is greater than 35% (loamy-skeletal).
4 Mixed, mesic Alfic Xeropsamment, generally meaning the soil is very young with little horizon development (enO, has a
sanch' or loamy sand texture with low coarse fragment percentage throughout (psamm), has developed under climate conditions of
wet winters and droughty, summers (xer), has some sign of leaching that indicates beginning of development into an more mature
soil t>.-pe, such as having higher clay content or base saturation in a B horizon (altic), has a mesic temperature regime (mean annual
temperature ranges from 8° to 15° C (47° - 59° F), and has no specific parent material mineralogy (mixed).
5 Sandy-skeletal, mixed, mesic Typic Xerorthent, generally meaning the soil has minimal horizon development (enO, has
no distinguishing characteristics at the Great Group level (orth=standard), has developed under climatic conditions of wet winters
and dr>.' summers is greater than 35% (sandy-skeletal).
6 Euic, mesic Typic Medisaprist, generally meaning the soil is dominated by organic rather than mineral components, is
greater than 20-30% organic matter (ist), has extremely- (as compared to slightly.- or moderately-) decomposed organic materials
(sap). is othenvise not very unusual for an organic soil (medi and typic), has developed under conditions of a mesic climate (mean
annual temperature ranges from 8° to 15° C (47° - 59° F), and has a pH of 4.5 or higher (euic).
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portions. The Casey is mapped along the eastern wetland-upland transition area as well as along
the lower western sideslope ofthe southern channel. The Dick soils are mapped on the upland
knoll that juts into the site about midway along the western edge. The Hoypus soils are mapped
across the rest of the western upland slopes with the exception of the southwest comer where the
Clallam soils are mapped. Please refer to the attached soil map for more details.
For your information, standard characteristics of the mapped soil series are described in
APPENDIX II. Please note that the SCS soil series maps and descriptions characterize expected
characteristics in only the top 60-100 inches of soil. Furthermore, the maps units can have
extensive inclusions of other soil types, and in some rare cases, can be entirely in error.
Site elevation ranges from highs of around 160 feet in the southwest comer and 145 feet in the
northeast comer down to around 108 feet in the base of the wetland at the northern boundary and
91 feet in the base of the wetland as it exits the site at the southern boundary.
,Vegetation
Vegetation in the swale area is a mixture of pasture grasses in the higher elevation sideslopes
grading to a predominance facultative, facultative wet and obligate species on the lower
sideslopes. The wettest portions of the swale in the northern portions of the property support a
variety of vegetation including (dominants are starred):
Scientific Name(acronym).. Common Name Indicator Statu~
Juncus effusus (JUEF)* soft rash FACW+
Typha latifolia (TYLA) cattails OBL
Circium edule (CIED)* edible thistle FACW-
Festuca rubra (FERU) red fescue FAC
Ranunculus repens (RARE) creeping buttercup FACW
The southem portions of the wetlands, as described above, become increasingly channelized
with pockets of open water and with a shrubby wet riparian area, including most of the plants
listed above, but also (dominants are starred):
Scientific Name(acronym), Common Name Indicator Status
Rosa pisocarpa(ROPI)* clustered rose FAC
Rubus spectabilis (RUSP) salmonberry FAC
Alnus rubra (ALRU) red alder FAC
Salix sitchensis (SASI).* Sitka willow FAC
Salix scoulerana (SASC)* Scoulers willow FACW
Equisetum arvense (EQAR)* field horsetail FAC
Urtica dioica (URDI)* stinging nettles FAC+
Veronica scutellata (VESC) marsh speedwell OBL
Malus fusca (MAFU) Pacific crabapple FACW
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Upland vegetation includes, but is not limited to (dominants are starred):
S~;ientific Name(acronym) Common Name Incli~ator Status
?seudotsuga menziesii (PSME) Douglas-fir FACU*
Sambucus cerulea (SACE)* blue elderberry FAC-
Symphocarpus albus (SYAL)* snowberry FACU
Pteridium aquilinum (PTAQ) bracken fern FACU
Polystichum munitum (POMU) sword fern FACU
Holodiscus discolor (HODI)* oceanspray not listed
Prunus emarginata (PREM) bitter cherry FACU
Rubus ursinus (RUUR) trailing blackberry not listed
Achillea millefolium (ACMI) yarrow FACU
Hydrology
The source of hydrology appears to be surface and subsurface flow along the base of the swale
via a channel system (a drain) that initiates about 1.mile north of the site. Wetland soils are
mapped along the base Of the broad swale that extends at least a couple of miles to the north. It
is unknown whether there are any perennial springs that might provide a year-round water
source, but water was observed within 20 inches of the surface even in late August, a time period
when most stormwater fed systems are dry. So it is assumed that there is at least some source
from springs, but the great annual flows are a result of winter precipitation and subsequent run
off.
The muck/peat soils are generally deeper, and may contribute some water to aquifer recharge.
However, the potential for recharge is very low in the finer textured soils mapped in the southern
portions of the site.
Wetland Classification and Rating
The Field Rating Form that documents the results of the preliminary wetland rating are provided
in Appendix II. If requested, a final rating can be provided with the Office Rating Form, which
can be filled out after results are returned from a State Agency database search. That search will
provide information about any documented occurrences of any sensitive, endangered or
threatened plant or animal species in the area around the subject property. At such time as
development is imminent, it is recommended to obtain that information. Until that time, the
wetlands are rated as a Category II system due to being rather large, having a variety of plant
species, and having a connection to significant upland habitat. Class II wetlands are given a 100
feet wide standard buffers for high intensity development proposals, and a 50 feet wide buffer
for low intensity development proposals.
Wetlands Regulatory Issues
If there are any proposed impacts to wetlands or the standard buffers as a result of this project,
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they must be permitted and mitigated for to some degree with the primary jurisdictional agency
being Thurston County for buffer and wetland impacts, the Washington Dept. of Fish and
Wildlife for stream impacts, and the Army Corps of Engineers for wetland impacts.
Jefferson County
In general, every effort should be made to minimize impacts to wetlands and buffers. No roads,
buildings or clearing should occur in the wetland or its buffers. In areas where impacts are
unavoidable, the County may allow impacts as long as they are mitigated for fully. Typically,
impacts will be mitigated for by either creating or enhancing wetlands, or enhancing buffers, the
specifics to be decided upon on a site by site basis. As any wetland creation or enhancement is
usually very costly, it is recommended to avoid impacts whenever and where-ever possible.
Any impacts to buffers will usually require a buffer enhancement plan in and adjacent to the
impacted areas. No guidance is provided in the ordinance about the required replacement ratios
for wetland creation mitigation projects. But typically, any impacts to wetlands will require at
least a 2:1 or 3:1 replacement of lost wetland acreage and restoration in areas temporarily
impacted. Often, it is required to complete mitigation before initiation of the primary project.
Army Corps of Engineers and. State Dept. of Fish and Wildlife
The COE regulates al__! Waters of' the United States, including streams and wetlands. The
WDFW regulates all salmon or fish bearing streams. Both agencies require notification and a
detailed project proposals.
If' the proposed impacts affect (in ~y way) more than 1 total acre of Waters of' the United States,
the COE will assess the actions to determine whether the proposal meets requirements of any of
their various conditioned permits. If impacts are less than I acre, the action is likely to be
permitted, but mitigation is generally required. If proposed impacts are greater tha~n 1 acre, but
less than 2 acres, the site may quali~ for a Nationwide Permit, as long as planned activities are
accomplished using best management practices and activities. If the proposed impacts are
greater than 2 acres, the site will be regulated under a COE Individual Permit process which is
much more costly than the Nationwide Permit process, requires a greater level of' report detail,
and is not automatic, i.e. the permit may not be awarded.
The WDFW will assess whether any proposed impacts will affect stream functions or fish
· habitat. They may require some mitigation for impacts, may require certain erosion control
operations and processes during construction and.may also require that construction occur only
certain times of the year, to minimize sedimentation in the creek.
SUMMARY
The 60* acre site has an approx. 11 acre wetland that includes a Type 3/4 stream (possibly an
old drainage ditch) in its southern portions. The wetland is predominantly Palustrine Emergent
class, but in its southern portions, also supports a Palustrine Scrub-Shrub wetland class along the
banks of the stream/ditch. The wetland rated as Category 2 wetland despite being rather
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severely impacted and degraded by fanning practices. The rating was most affected by the
number of plant species, and the proximity to the adjacent upland habitat. The wetland is given
standard 100 feet wide buffers for high intensity development and 50 feet wide buffers for Iow
intensity development under the Jefferson County Interim Critical Areas Ordinance. As there is
no current site development plan, no specific comments can be provided on any proposed
impacts to the site wetlands or buffers.
Aside from Jefferson County regulatory authority described above, any impacts to the wetlands
and the associated creek are also regulated by the State Dept. offish and Wildlife and the
Federal Army Corps of Engineers. All three agencies will require a proposal and justification
for any proposed impacts before they will issue the necessary permits for the proposed activities.
I hope this report provides adequate information for you to proceed with project planning, If you
have any questions, please feel flee to call and discuss. ' '
Wetlands specialist
ARCPACS certified soil specialist
Certification//3313
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