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HomeMy WebLinkAboutHabitat Management Plan 502313050Habitat Management Plan Grau Property 384 Forest Drive Brinnon, WA 98320 April3,2002 Prepared by: Kathleen W. Smayda, Biologist Smayda Environmental Associates, Inc. 139 NE 61st St, Seattle, WA 98115 206-522-6199 1. Introduction The Grau property is located at 384 Forest Drive in Brinnon, Washington. It is listed as Jefferson County tax parcel # 502-313-050. An unnamed, seasonal stream runs through the property, entering a culvert about 50 feet south of the northeast comer of the property. This Type 5 stream does not support fish, but enters the fish-bearing waters of Hood Canal within 1/4 mile of the eastern property boundary. The Grau's propose to construct a single family home on the site. The comers of the proposed structure have been located on the ground by the landowner. A portion of the proposed exterior deck on the north side of the home will be located within the county- designated 50-foot streamside buffer. This report provides details on the locations of the streamside buffer and the proposed structure, and provides a proposal to use buffer averaging and enhancement of the forested habitat to offset the buffer width reduction. 2. Type 5 Stream and Streamside Buffer Figure 1 shows the location of the Type 5 stream on the Grau property. The seasonal stream enters the property about midway along the western property boundary and continues generally northeast across the property, exiting via a culvert near the northeast comer. Previously, an additional 20' length of 18" culvert pipe enclosed the stream near the eastern property boundary; this culvert was washed out during winter 2001-2002, exposing the stream bed. A smaller side drainage joins the stream in the northwest quarter of the property, draining from a recently clear-cut slope above. The stream is incised and actively eroding downward, apparently at least in part as a result of the recent clearcut. ~ Grau Property Habitat Management Plan The majority of the property and the streamside buffer is moderately to heavily wooded with young second-growth western hemlock (Tsuga heterophylla), western redcedar (Thuja plicata), big-leaf maple (Acer macrophyllum), and red alder (Alnus rubra), bittercherry (Prunus emarginata), and a few Pacific yew (Taxus brevifolia). Evidence of historic logging is present in the form of large diameter stumps with springboard notches. More recent logging of second-growth trees is also evident. Mature trees on the site exceed 80 feet in height and 2.5 feet in diameter. Common shrubs within the streamside buffer include red elderberry (Sambucus racemosa), Indian plum (Oemleria cerasiformis), salmonberry (Rubus spectabilis), and thimbleberry (Rubus parviflora). Red huckleberry (Vaccinium parvifolium) and Pacific rhododendron (Rhododendron macrophyllum) are present in drier locations of the property. Other understory plants in the streamside buffer include swordfern (Polystichum munitum), lady fern (Dryopterisfelix-femina), licorice fern (Polypody glycyrrhiza), piggy-back plant ( Tolmeia menziesii), woodland strawberry (Fragaria vesca) and bedstraw ( Galium sp.). Non-native plants observed in the streamside buffer include foxglove (Digitalis purpurea), Himalayan blackberry (Rubus discolor), evergreen blackberry (Rubus laciniatus), bull thistle (Cirsium vulgate), and bugle (Ajuga reptans). Scot's broom (Cytisus scoparius) has been removed from other portions of the property. The building site and adjacent area along the eastern property boundary are not wooded. Turfgrass lawn is present along the eastern boundary near the northeast corner and near the building site. The access to the existing well is also non-wooded. Figure 1 shows the location of the 50-foot streamside buffer required by Jefferson County. This buffer totals approximately 1.03 acres, with an estimated 0.91 acres in forested habitat and 0.12 acres in turfgrass or other non-forested condition. The southern portion of the stream buffer near the proposed construction site is wooded with a few 6 to 8-inch hemlock and several multi-stemmed big leaf maples of fifteen to twenty-five feet in height. Sword fern and Indian plum are present in the understory. The easternmost section of the streamside buffer is not wooded, but is managed as turfgrass lawn with a small orchard near the northeast corner of the property. A shed is located about 10 feet south of the stream near the eastern property boundary. The stream was previously enclosed in a culvert near this location. 3. Proposed New Construction Figure 1 shows the building site for the proposed single family residence. The County requires a 5-foot building setback in addition to the 50-foot streamside buffer, for a total of 55 feet. The northern edge of the proposed deck will be located 41 feet from the ordinary high water mark (OHWM) on the south bank of the stream (Point A on Figure 1). At Point B on Figure 1, the deck will be 51 feet from the OHWM. All other portions of the proposed structure are to be located outside of the 55-foot buffer and setback. Smayda Environmental Associates, Inc. 2 April 3, 2002 Grau Property Habitat Management Plan The proposed buffer/setback width reduction will be a maximum of 25 % smaller than the standard buffer/setback (41 feet of 55 feet at Point A), and will extend for a distance of 30 feet. The streamside buffer will be reduced in area by approximately 0.01 acre as a result of the construction. The portion of the streamside buffer to be affected by the construction in non-forested; no trees will be removed from the buffer as a result of construction. The area to be affected is presently vegetated with grasses and forbs, and is partially gravelled. Relocation of the proposed structure to avoid the buffer incursion would require removal of one western red cedar of approximately 2.5 feet in diameter and twenty.or more 2 to 3- inch diameter red alder and bittercherry. 4. Buffer Averaging In order to offset the loss of non-forested habitat from the streamside buffer at the building site, the landowner proposes to provide additional buffer width along the upper portion of the stream. Figure 1 shows the proposed location of the revised buffer along the south side of the upper portion of the stream. In this reach, the buffer will be widened to an average of 75 feet from the OHWM. The standard streamside buffer would provide approximately 1.03 acres. The revised streamside buffer will incorporate a reduction of 0.01 acres at the building site and an addition of 0.09 acres in the southwest portion of the property, for a total buffer area of 1.11 acres. 5. Habitat Management Plan In order to ensure proper functioning of the revised streamside buffer, a Habitat Management Plan has been developed. The Habitat Management Plan will serve as an owner's manual for management of the streamside buffer, describing acceptable and desired practices as well as prohibited activities. The streamside buffer will be managed by the landowner in a natural condition. Native vegetation will not be cleared from the site. Minor pruning of vegetation to enhance views or permit access will be allowed as long as the function and character of the buffer are not diminished. The portions of the streamside buffer that are currently managed as turfgrass lawn will be retained as such. However, no additional lawn areas will be established within the streamside buffer. In order to improve the value of the streamside buffer in terms of soil stability and wildlife habitat value, the landowner will undertake the following management activities: · Control ofinvasive non-native species; · Enhancement of streamside buffer with plantings of native species; · Retention of dead and downed wood; · Restriction of domestic grazing animals; and · Avoidance of pesticide / herbicide / fertilizer use. Smayda Environmental Associates, Inc. April 3, 2OO2 Grau Property Habitat Management Plan Control of invasive non-native species. The landowners have aggressively controlled invasive non-natives on the site for four years and will continue weed control in the future. Eradication of Himalayan blackberry, evergreen blackberry, bull thistle, and Scot's broom is the goal for the streamside buffer. Other invasive non-native species will be controlled to prevent their spread within the buffer. Non-native species common to the region that could occur within the buffer in the future, and should be controlled, include: English ivy (Hedera helix), Japanese or giant knotweed (Polygonum spp.), tansy ragwort (Senecio jacobaea), and Canada thistle ( Cirsium arvense). The landowner agrees to use physical and mechanical methods such as pruning, hand- pulling, and grubbing of roots to control invasive non-native plants within the streamside buffer. Chemical controls will not be used. Additional information on weeds and weed control will be sought from the Jefferson County Weed Control Board (360-379-5610). Enhancement of streamside buffer with plantings of native species. The forested portion of the streamside buffer will be enhanced with rooted cuttings and/or 1- to 2-gallon sized rooted stock of native shrubs, forbs, and small trees. A total of 40 plants will be installed in the following proportions: approximately 10 trees, 20 shrubs, and 10 forbs or ferns. A list of native species recommended for the site is provided in Table 1. Table 1. List of Recommended Native Plants for Enhancement Plantings Trees Western red cedar Thuja plicata Western hemlock Tsuga heterophylla Western flowering dogwood Comus nuttallii Bitter cherry Prunus emarginata Shrubs Indian plum Oemleria cerasi, formis Red flowering currant Ribes sanguineum Oceanspray Holodiscus discolor Cascara Rhamnus purshiana Pacific ninebark Physocarpus capitatus Baldhip rose Rosa gymnocarpa Oregon grape Mahonia nervosa Mock orange Philadelphus lewisii Ferns / Forbs Swordfern Pol?stichum munitum Piggy-back plant Tolmeia menziesii Fringecup Tellima grandiflora Bleeding heart Dicentraformosa Vanilla leaf Achlys trifilla Western columbine Aquilegiaformosa False lily of the valley Maianthemum dilatatum Smayda Environmental Associates, Inc. 4 April 3, 2002 - ' Grau Property Habitat Management Plan Enhancement of the buffer vegetation will increase plant species diversity and stem density within the understory. This will increase wildlife habitat value related to structural complexity and forage. The increase in rooted vegetation will contribute to the stability of streamside soils. Plantings should be performed in mid- to late fall or early spring for the best chance of survival and least need for supplemental watering. Installation should be performed with minimal disturbance of soils and existing vegetation within the streamside buffer. Additional information on the availability and suitability of native plant species and planting methods will be sought from the Jefferson County Conservation District (360- 385-4105). Retention of downed woody material. The landowners have adopted the practice of retaining dead and down woody material in place within the forested area of their property. Under the Habitat Management Plan, this practice would continue, with all stumps (from historic logging and natural deadfall), limbs, and logs retained on-site within the streamside buffer. Retention of woody material enhances microbial and wildlife habitat, and provides nursery sites for many plant species. Control of domestic grazing animals. The streamside buffer will not be used to pasture, graze, or tether domestic animals. If cows, horses, goats, or pigs are present on the property, they shall be restricted from grazing within the streamside buffer area. Pesticide / Herbicide / Fertilizer Use. Pesticides, herbicides and fertilizers will not be applied within the streamside buffer. Organic compost and/or mulch may be applied at the time of planting of native species. 6. Construction Management During construction, the landowner will post the perimeters of the revised streamside buffer with temporary signs at an interval of one per 100 feet (minimum). Additional signs will be placed if necessary to clearly indicate the buffer in the vicinity of the house construction site. The signs will remain in place prior to and during approved construction activities. The signs will be worded: 'Buffer - Do Not Remove or Alter Existing Native Vegetation'. Smayda Environmental Associates, Inc. 5 April 3, 2002 APPROVED , _ DEPT. OF COM~ .UNITY storm.,w~ter ~[;s Required~~:~.--- Robert & Diane GRAU 384 Forest Drive Brinnon, WA 98320 ,..:-'-:.-~L"~-~,.~..~ ::: .-'-.:.;:: 'i-':. '::-:..;.'.-.-:i., :.. ~-.--'..: :i'-:-' !."-::'i :'--. ;:. :'. ::'..-. :":- - , '.-ii,. i:.-:.' , F'"~.~c~¢ ~u~'~-. ::. "':'......." "-:-:~" -J ". -: '. -~ ".- .; ':- ~':"C':,' ,' ".,.' '-"- ' I. Existing' 18'f Culvert ,- -: ':.-. '. ".. -. :..-: 7' .-xk, -;.',.--:::';: .:'-:-..--... ---.X:.,-: :.: -' ~""':": ";;": ..-i.':..-.'.' ;'-:,:;.--;:: :...::.:...-;:v~' ..,-,'i~.:'.....:.i-~ :~ .':'-'.;; .... ' .--- -- '."":. "-.,' . I--.z-_ . :':: .... :: ! :..'.-.' -; -::f,;Y?..-~"'~ , .... ':':". ': "-'-."';" "..~ '."-' i..".-.: "':':-':...';;; :'"-.::: .,"":.,. '.-:: :'-.-':' ..~.'.-" .: ':.~ ,./ ~ . - - I".;:": ;.'""'L '] ':'.. ' .::.' ..... 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'.-:. :'. · :'-.?'..-."...'~; ~,~.~ ~.~-~.,'-."': .'-'...' "' '/"" :-' "' ".b-/~ ' '"" '.":: ':'. ~ " : :. './'"...'"' ...~.: Revi~ed~:Stre'~m'Sid~.Bi~'.ff, eff -'. '.'.":.. "-."'¥ .: .... "~i'. :' ':"-'".-'""'-'"" '~, .'/., -: ,Tx~ ~"..: .' 4, .: ' .~;~s.t,~'~ -' "- ' ... ":. :. :..., :IF.,.""'.:". ~-.. :.: ' I/'""".. -'.... ""...'. :...:. -. '-"'.' .T.' .c~h~:.TM . ." :-" "" :' '"'" " .... : '..":' :. ' ":.' ' :" Map base: Armstrong Homes of Bremerton, Inc., Grau Site Plan 2002 Map Revised 4/2/02 by SEA, Inc. Based on field inspection 3/29/02. Locations of feature¢ are approximate. Standard 50' streamside buffer on north of stream not depicted. ' Stippling indicates forested habitat. Figure 1. HABITAT MANAGEMENT PLAN NAP