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HomeMy WebLinkAboutWetland Delineation 901263005 ,). February 1, 2007 RE('~WEO FEB 0 5 2001 JfHtRSU~~""NlV nr." Richard Brees 407 Embody Road Port Ludlow, W A 98365 Re: Wetland Delineation and Categorization for the 2.75 acre parcel at ,2743 Center Road, in Jefferson County, Washington (Tax parcel No. 901 263 005). The parcel is located in the SE 1/4 of the SW 1/4 of Section 29 N, Range IE. WM. Dear Richard: The wetland delineation was conducted on September 21, 2006 to matk ,the wetland boundary on the above referenced p~rcel. The delineation was conducted, using the Department of Ecology, Washington State Wetlands Identificationimd Delineation Manual . (Publication #96-74), as required by the Jefferson County Code. This manual utilizes the three parameter methodology to determine the presence or absence of wetlands. thethree parameters include wetland ,hydrology, hydric soil, and'hydrophytic vegetation and positive indicators of all three wetland parameters must be preseIit for an ~ea under' normal circumstances to be considered wetland. The use of this manual and the three wetland parameter methodology on this parcel revealed that the site is under notmal circumstances so the Routine On-Site Determination Methodology was used to delineate the on-site wetland. This ,2.75 acre parcel is located at 2743 Center Road in Jefferson County, .Washington. The property is bordered to the south, east and north by homes and mobiles on similar sized lots ,and to the west by Center Road. The irregular shaped parcel is currently undeveloped, but appears to have had a mobile home that was recently removed in the southwest comer. There is an old well house remaining from the past occupancy that sits along the south property line. An unpaved road, accessing the parcel to the east cuts through the 1015 S.W: Harper Road, Port Orchard, Washington 98367 (360) 876-2403 Fax (360) 876-2053 o .l Brees February 1, 2007 Page 2 center of the property in a west to east orientation. The two wetlands' sit on both sides of the access road and it is unclear if they were historically connected prior to construction of the road, although the topography and water building up behind the road indicate a possible historic connection. It appears now that. they are functioning as a separate systems. A stream flows thiough the low a,reas of the southern wetland from south to north that appears 'to be a Type 3 or 4 wa~r. The stream flows west under Center Road through an old culvert. There is also a non fish bearing stream mapped by Jefferson that runs west along the north 'property line that appears to have been ditched into a different location draining northwest on the neighboring property to tbe north.. See attached map for location of wetlandS and stream on site. Two wetlands were identified on the parcel, one that enters the site from the south and runs in a long swath along both sides of the stream south of the access road until it reaches, Center Road (W'etland A). The other wetland encompasses most of the north. side of the access road and was not delineated. Wetland extends off site on all sides of the property, excluding the west line along Center Road. The south side of Wetland A was' delineated, adjacentto the proposed buildin.g site. Wetland A is a Category n Palustrine wetland that . appears to have seasonally flooded hydrology and exhibits emergent, scrub shrub and forested wetland vegetation classes (also possible aquatic bed off site to the south). The other wetland on the north side, of the road is completely forested. Wetland A and the stream within will both require 100 foot natural or existing vegetation buffers according to the Jefferson County Critical Areas Ordinance. The wetland buffer is more restrictive than the stream buffer because it overlaps the stream buffer and therefore the wetland buffer will be the regulated buffer. The proposed new activity on the property includes the placement of a new home and septic drainfield with an associated driveway. (See attached site plan). ,1 Brees February 1,2007 Page 3 It appears from the site plan that portions of the home and driveway are proposed within the boundaries of the wetland and that portions of the home; driveway and septic diainfield are also proposed within the 100 foot wetland buffer. This letter includes a description of the data collected, the wetland category, required buffers and background information on the site obtained from the N ational Wetlands Inventory, and Jefferson County Soil Survey. The on-site soils are mapped as AlC Alderwood gravelly sandy loam,. 0-15 % percent slopes in the western third, Wa Wapato silty clay loam, 0-3% slopes through the center and AlD Aldeiwood gravelly sandy loam"15-30% slopes on the eastern third, according to the Soil Conservation Service (now the National Resources Conservation Service), Soil Survey of Jefferson County Area, Washington, Au~t 1975. Alderwood soils are not classified as hydric and Wapato' is classified as a hydric soil. The soil survey also maps the stream through the site that appears to start off site to the.south and flows north through the location of Wetland A. See' enclosed map for site located on the soil survey and see enclosed soil descriptions for additional'infonnation on the mapped soils. The US Fish and Wildlife Service (USFWS), National Wetlands Inventory (NWI), Center Quadrangle, maps a Palustrine Emergent Seasonally Flooded wetland on the south end of the property with another larger system of the same class off site to the south. From on site observations it appears that the two systems are connected (are considered one system) and also contain Forested, Scrub Shrub and possibly Aquatic Bed vegetation classes. The NWI also maps a Palustrine Emergent wetland with Temporarily Flooded/Partially Drained- Ditched hydrology west of the site across Center Road. ,The NWI maps no other wetlands on or within 250 feet of the site. The Jefferson County Critical areas mapping indicates the presence of wetlands on the eastern half of the parcel which extend off site to the south. See enclosed map for site located on the NWI and Jefferson County Critical Areas Map. ,) Brees February 1, 2007 Page 4 The south side of Wetland A is delineated; in the area adjacent to the proposed home site and is marked with 10, consecutively. nUDibered orange flags. Data was collected at four test holes, two within the wetlands and two ,within the uplands to verify the wetland edges and to document wetland and upland conditions on site. At each test hole, a 16-inch soil pitwas completed to document the presence or absence of hydric (wetland) soil conditions (dark soil colors 'with or without mottling), and the presence or absence of wetland hydrology indicators (indicators, includ~ standing water on surface or in test hole; surface scouring; water stained vegetation; drift lines; and/or oxidized root channels in the soil). In a 30~foot diameter circle around these test holes, the dominant vegetation was recorded in order to determine whether or not the hydrophytic vegetation criterion is .inet. If there is greater than 50% cover by plants having indicator status of FAC (34-66% of the time in wetlands- equally likelyin wetlands and uplands); FACW (67-99% of the time in wetlands); and/or OBL (greater than 99.% of the time in wetlands)~ then the hydrophytic vegetation criteria is met. See attached drawing for approximate location of the test holes and Data Forms 1-4. Test Holes 1 and 2 are located in Wetlartd A to verify the presence of wetland conditions and to document the physical characteristics of the wetland. Test Hole 1 is in the emergent portion of the wetland approximately 20 feet east of the old well house. Test Hole 2 is located downslope in the wetland drainage in another emergent portion of the wetland that was very saturated during the summer months. The vegetation at both test holes is characterized by mixed emergent vegetation composed of slough sedge (Carex obnupta) OBL, soft rush (Juncus effusus) FACW +, creeping buttercup (Ranunculus repens) FACW, reed canarygrass (Phalaris arundinacea) FACW and horsetail (Equisetum arvense) FAC. There are a few scattered patches of hardhack (Spiraea douglasiz) F ACW, Sitka Willow (Salix sitchensis) FACW and Pacific willow (Salix Lucida ssp. lasiandra) FACW + throughout the on site portion of the wetland. Red alder (Alnus rubra) FAC and western red cedar (Thuja plicata) FAC overhang the wetland fringes. Data was not collected in the forested portions of the wetland just off site to the south but a forested vegetation class was observed. 1 Brees February 1, 2007 Page 5 The soil holes at Test Holes 1 and 2 revealed single and double layer tine sandy loam profiles. The soil at Test Hole 1 consists of a single layer profile (0-16") that has a matrix chroma of 10 YR 2/1. The soil hole at Test Hole 2 consists of a double layer profile that has a 12 inch 'tine sandy loam surface horizon (0-12") that has a matrix chroma of 10 YR 2/1 and a fine sand subsurface horizon (12-16") that has a matrix chroma of 10 YR 3/1. Both of these soil, profiles are considered hydric because they have low matrix chromas andlor low matrix colors with mottles at depths below 10 inches in the soil profile. Wetland hydrology was present at the time of the site visit in the form of soil. saturation to the surface in both test,holes. The source of hydrology for the wetland appears to be from stream flows and seasonal surface runoff. Both Test Holes 1 and 2, exhibit a dominance of hydrophytic vegetation, and hydric soil profiles. and primary indicators of wetland hydrology are prese:Q,t indicating that the area tests positive for all three wetland parameters, therefore the area was delineated as wetland. Test Holes 3 and 4 are located.in the uplands between the proposed home site and the wetland. The uplands form a triangular shape in the southwestern comer of the property. Test Hole 3 is located in the northwest comer of the triangle and Test Hole 4 is located near the eastern comer of the triangle very close to the well house. The vegetation at Test Hole 3 is dominated by a sparse tree layer of domestic apple (Malus domesticus) NI (Assumed FACU), and a domesticlwild cherry cross (Prunus Xpugetensis) NI assumed FACU. There is mixed percentages of Indian plum (Oemleria cerasiformes) FACU, serviceberry (Amelanchier alnifolia) F ACU and Himalayan blackberry, (Rubus armeniacus) F ACU in the shrub layer. The herbaceous layer is dominated by scouring rush (Equisetum hyemale.) FACW- and Canadian thistle (Cirsium arvense) FACU. The weedy vegetation at Test Hole 4 is dominated by grassy areas dominated by tall fescue (Festuca arundinacea) F ACU, stinging nettle (Urtica diocia) FAC+ and Comfrey (Symphytum officianale)NI. There is a Brees February 1, 2007 PClge 6 sparse tree layer of Oregon Ash (Fraxinus latifolia) FAC and old landscaping trees, with low percentages of California huckleberry (Vaccinuim ovatum) FACU and Holly (Rex aquifolium) Assumed FACU in the shrub layer. The soil hOles at Test Holes 3 and 4 revealed double layer fine sandy loam to gravelly sandy lOam profiles. The soil at both test holes revealed a 5 inch surface horizon (0-5") with a matrix chroma of 10 YR 3/2 with no mottles. The subsurface horizon (5-16") has a inatrix chroma of 10 YR 4/3 at Test Hole.3 and a matrix chroma of 10 YR 4/4"at Test Hole. 4. Both of these soil profiles are not considered hydric because they have .high matrix chromas at depths below 10 inches in the soil profile. No hydrology of evidence of wetland hydrology waS present at either of the upland test holes. nor were they dominated by hydrophytic vegetation. Both Test Holes 3 and 4 do not test positive for any of the three wetland parameters, therefore the area is not considered wetland. This wetland has been categorized using the Washington State WetIarids Rating System for Western Washington. Wetland systems are rated as one entire system, not just the on-site portioll of the system. (See attached photo showing the wetland unit being rated). The on- site portion represents the northern tip of the wetland being rated. The wetland meets the current requirements of a Category II wetland because it is approximately 5-6 acres in size, has been historically impacted and appears to have four classes of vegetation (emergent, scrub shrub, forested arid aquatic bed), so it has high interspersion of vegetation classes. No roads or paved areas are within 100 feet of the wetlai1d for more than half of the circumference and the wetland has a vegetated. corridor. leading to significant undeveloped land to the east. Wetland A provides a year round source of fresh water to a fish bearing stream (Chimacum Creek) through culverts under Center Road. Under the new Washington State Wetland Rating System for Western Washington revised edition (#04-06- 025) that may soon be adopted. by Jefferson County, it appears that the wetland would rate Brees February 1, 2007 Page 7 as a Category m an~ would have different buffers than are currently required. See attached wetland rating forms and photo outlining unit of wetland being rated. Category IT wetlands require 100 foot buffers with a 5 foot building setback from the buffer edge according to the current Jefferson County Critical Areas Ordinance. The wetland buffer is to be. measured horizontally from the delineated wetland edge and is to remain in existing or native vegetation. No existing vegetation is to be removed from the wetland buffer without prior permission from Jefferson County. Native vegetation planting is encouraged within wetland buffers to add protection to the wetland in areas that are previously disturbed, although it is likely that the countY will need to be notified of the plantiJig. See attaChed sections c:)f the Jefferson County Code. A single family home, driveway and septic drainfield are proposed in the southwestern comer of the property roughly where the old mobile home used to sit. See attached site plan. It appears from the survey conducted of the wetland boundary and 100 foot wetland buffer that there is limited space available outside of the 100 foot wetland buffer to place the home and septic drainfield. Wetland buffers can be reduced through processes laid out in the. Jefferson County Unified Development Code 18.15.340 Protection standards Reducing Buffer Widths: The Administrator may reduce the standard wetland buffer width, when the project applicant demonstrates both of the following to the satisfaction of the Administrator. i. Standard wetland buffer width averaging as set forth in this section is unfeasible. Buffer averaging is unfeasible because the wetland buffers appear to extend off site on all sides of the property, excluding the small area in the southwest property comer where the septic is proposed. ii. The project application includes a buffer enhancement plan using native vegetation which substantiates that an enhanced buffer will improve the functional attributes of the buffer to provide additional protection for functions and values. Brees February 1, 2007 Page 8 Since Wetland A contains what appears to be a Type 3 or 4 stream (100 foot buffer), it too will need to be asseSsed if buffer reductions are considered. The 100 foot stream buffer is to be measured landward from the ordinary high water mark. It appears that the stream buffer is encompassed completely by the wetland buffer, but if the wetland buffer is reduced to the level of the stream buffer, the stream buffer requirements will need to be considered. The Jefferson County Unified Development Code Section 3.6.9. Reducing Buffer Widths for streams states that: The Administrator may reduce the standard buffer width when the project applicant demonstrates the following to the satisfaction of the administrator: i. Standard buffer function will be preserved through such mechanisms as buffer averagitig or enhancement with native vegetation. ii. A Habitat Management Plan is required for all (stream) buffer width reductions including buffer averaging. ill. Under no circumstance shall (stream) buffer wiqths be reduced by more than 25%. The proposed site plan shows possible wetland impact at one corner of the home and the eastern portion of the driveway. A utility line is proposed across the wetland/stream to the proposed well on the north side of the access easement road. Wetland fill may be allowed if no other reasonable alternative exists and a proper wetland mitigation sequence plan is approved by the Administrator. Brees February 1, 2007 Page 9 Jefferson County Code 18.15.350 Mitigation states that: The overall goal of mitigation shall be no net loss of wetland function, value, and acreage. 1 ) Mitigation Sequence. Mitigation includes avoiding, minimizing, or . compensating for adverse impacts to regulated wetlands ortheir buffers. When a propOsed use or development activity poses potentially significant adverse impa~ts to a regulated wetland or its buffer, the preferred sequence of mitigation as defined below shall be followed unless the applicant demonstrates that an overriding public benefit would warrant flO. exception to.tIDs preferred sequence. (a) . Avoiding.the impact altogether by not taking a certain action or parts of actions on that portion of the site whichcontaiDS the regulated wetland or its buffer; (b) Minimizing impacts by limiting the degree or magnitude of the action and its implementation; ('c) Rectifying the impact by repairing, rehabilitating, or restoring the affected environment . d) Reducing or eliminating the impact over time by preservation and maintenance operations during the life 'of the action; or (e) Compensating for the impact by replacing, eilhancing,or providing substitute resources or environments. (2) Compensatory Mitigation ~ General Requirements.. As a condition of any permit or other approval allowing alteration which results in the loss or degradation of regulated wetlands, or as an enforcement aCtion pursuant to Chapter 18.50 ICe, compensatory mitigation shall be required to offset impacts resulting from the. actions of the applicant or any code violator. (a) Except persons exempt under this article, any person who alters or proposes to alter regulated wetlands shall restore or create ,areas of wetland equivalent to or larger than those altered in order to compensate for wetland losses. The following Table 3-5 specifies the ratios that apply to creation or restoration which is in-kind, on-site, and is accomplished prior to or concurrently with alteration: Table 3-5. Required Replaeement Ratios for Compensatory Wetland Mitigation Wetland Category Creation and Enhancement (2) Restoration (1) I 6:1 12:1 II or ill . Forested 3:1 .6:1 -- Iil1 1\1 ~- 5 all IV 1.25:1 2.5:1 Brees February 1, 2007 . Page 10 Wetland A is a Category n WetIandand the proposed area of impact is located in a scrub shrub/emergent portion therefore the ratio for CompeIl$",tory Wetland Mitigation requires. a . wetland creation and restoration ratioof2:1 or Wetland.Enhancementof4:1: (See Table 3- 5 above). Crossing a wetland with .a utility line may be allowed as lOng as aplan is proposed that restores any disturbed areas of wetland and buffer by backfilling any soils . that are removed and replanting with native vegetation along !be utility line. In summary, a single family home is proposed on the 2.75 acre p;rrcel at 2743 Center Road in Jefferson County, Washington. A Category IT wetIand requiring a .100 foot natural vegetation buffer was identified and the south edge adjunct to a proposed home site was" delineated in the.southwestem corner of the property. The parcel is irregularly shaped" lot is surrounded by Center Road to the west and)ots containing homes and mobiles to the south,east and north. An unpaved road cuts through the center of the property off Center Road, allowing access to a home~and"parcel to the east. The parcel is undeveloped but appears to have recently had a dilapidated mobile removed in the southwest corner that was accessed via a communal drive along the south line that also access two mobiles on the neighboring property. A home is proposed in the sam~ general vicinity as the old mobile home within the 100 foot wetland buffer. It is not clear exactly where the mobile sat as there was. no cement foundation. A septic drainfieldand driveway are also proposed in the southwest. corner of the property. A Wetland A is a Category II Palustrine Emergent/Scrub Shrub/Forested! Aquatic Bed wetland with a seasonally flooded/permanently flooded hydrologic regime. The on site portion of the wetland that is. a small part of the larger system that sits mostly off site in a small valley to the south. Wetland A is fairly narrow and the on site portion remains south of the dirt access road that cuts through the center of the property. The southern edge of Wetland A was delineated adjacentto the proposed building site. Another wetland Brees February 1, 2007 Page 11 encompasses most of the north half of the property on the north side of the access road. It appears that the two wetlands may have historically been connected prior to the construction of the access road. Wetland A will require a 100 foot natural or e~sting vegetation buffer with a 5 foot building and impervious surface setback according to the Jefferson County Code. The wetland buffer is to be measured horizontally from the wetland edge and the setback is to be measured from the outer edge of the buffer. It appears from the site plan that the home and portions of the drainfield are proposed within the 100 foot wetland buffer and ,that portions .of the home and driveway are also proposed within the wetland. The Jefferson County regulations guiding wetland and stream buffer reductionsan.d wetland :flU have been laid, outinthis letter to provide information on how to pr<?Ceed with.the current site plan. No official buffer enchantment of wetland mitigation plan has been prepared at this time. If you have any questions concemingthis delineation, please feel free to contact me at (360) 876-2403. S,cerelY, -.) -<. Jl{LtC.YLL(\ )(l~LCt1-H Joanne Bartlett Professional Wetland Scientist .~~ Mudra Bergan Biologist / \ - " . lit. ~ ~" ....... '-' eff .,.~t --=-.... Wt+lcuot J, ...... ,,"" '- -.. - -- :t ~ lJ';. ....... ~ ~ ra.S'" ~ , -,," =-' ""'__ __ __ r ~- -- a~ lfJtwJ - ~ '" .~ "I t) o I:) ~ <::) Gl n~kcL (,rlDt~ '\<.,c1o..v d 'B<< ~ ~ 40~ e:M~J.j~~d Por +- \""'uollowW At s;Jt1 ~ ~ 141> CelA ia.r ~~d ;;<J1S- MrtS Ta'( fAtf'"re{ ;J 0 ;. t{ 0 I 2 (0"3 OO? 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