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Draft NRMP Section 2 Section 2: Background Introduction This section provides a background information related to Golden Valley's location within the Twin Cities Metro Area. It also provides a brief discussion of the natural conditions found below, within, and at the surface of the city's landscape. This includes topics on geology, hydrology, soils, pre-European settlement vegetation, wildlife and existing land use. Since the plan is intended to guide natural resource management practices including public outreach and education programs and funding procurement, this section also includes a discussion of existing management efforts. Location The City of Golden Valley is a well-established first ring suburb located in Hennepin County (Figure 2.0). It is bordered by the cities of New Hope, Crystal, and Robbinsdale to the north, Minneapolis to the east, St. Louis Park to the south and west and Plymouth to the west. Figure 2.0: Location Map Mata Wove County County Ramsey County City W Golden Why Carve' County D,Aora Scor County County Golden Valley Natural Resources Management Plan 2015 Background Page 9 Natural Resources The City of Golden Valley contains a rich stock of natural resources that contribute to the community's character, health and quality of life. Preservation, conservation and enhancement of these resources are critical to the community. The City's natural resources include air, water, and land, and a range of soil types including those that are suitable for woodland, forest and native prairie management and enhancement, native plant communities, diverse wildlife, and a number of lakes, streams, and wetlands. To gain a better understanding of Golden Valley's natural resources, a brief discussion of resources that that lie below the ground (geological features), in the ground (soil characteristic) and on the ground (water bodies, streams and wetlands, and vegetation)are included in this section. Bedrock Geology Below everything that is visible at the surface of the earth is a continuous, complex layer of solid rock known as "bedrock". Typically, bedrock is covered by water, ice, snow, soil, loose sediments, vegetation and man-made structures. Bedrock is seen at the surface of the landscape as "outcrops," and occasionally observed as road cuts or through excavation. It is the bedrock materials that provide insight into the history of the earth. It also helps to define the structural character of the landscape and provides the beautiful scenic views when exposed as can be seen driving along the Mississippi and Minnesota Rivers. Figure 2.1 shows the bedrock underlying the majority of Golden Valley to consist of St. Peter Sandstone, a soft pure quartz sand layer sandwiched between the Prairie du Chien group, (hard limestone/dolomite) and Platteville & Glenwood formations (finer grained and softer limestone). (Geologic Profile to be placed here) Golden Valley Natural Resources Management Plan 2015 Background Page 10 Figure 2.1: Bedrock Geology L-..- . Cay of Golden Valley Limits igl, Bedrock geologyIR NB Praire du Chen Group Platteville aid Glenwood Formations St Peter Sandstone ; `s*,,it t1 !+ Sethi . ',,.._ ' . ' L 1 i-,--, tall. ,1,-Ii„,..„- 1,-,---i0!-, ut!,-. \,;k,->10,1::::,:i1.7. �,.� �J£�4 i:• .e le:»t t::� s ]Ff.� ts::S �� iS 1F ��, . q I t l V r-hr 7 .1, • - •.• i k l.,-. c , ,1 ,+NLi* ' 'it.,--:4, Jnr T •to+,�� _7t y cs F ::nasi •-.f_:.. di.; _l = S+ l lLih a l•y- , } z ,7.Iv:. tw,i a-4-r. r via tu.---"",,,li= '.��...., .,,r qtr %..:_. \ <"`.`, o''t __, n7 rT- 7 j i n�4/i' r _ f '�ln"e"moi' L. s•�N�,�iN f" _.:'` �/ __:___ ia .. }}�,+w�. n � 1 11 13Ic 31,t ' �.`='x- 1 ^,,,. � i,. ai�--�imp- .i``"' ....� _`i+��( i.Y?rte.'+-� ..-bawl I ..,...y---� J J i II _ 4.i4 lie 7.r--.,zE,�.�aye �.r �."-gyp l '-t .r �s� 'r, ia ,, m ! -1911 , Tr-- i- - - NI . ..1 . ti ) : 2 d .76 ...leTT,pr L. ` -: JHNLt: :Z '�l1tacjiIN . ;ili Mil itLi, # Ly4— r'':�C,{i _ "=;c P.�'' rnLiGS, C r- `� fl .,'... - , i. .:?•-mil. i..1S.�S ice, jell '.H .1. f_:.i: �.�1 1:14 " ■ _111—�I„r __ . 4. 1�..t;-gi' s iz� 'r Lia— Ei pl�qq ;� ��r:.'gC ' mYri7%%fs: 'l i �, r t. ..,:.-� + .. ...,u.�rNli ':'I.ir. i�f 11- vs Platteville and Glenwood Formations The Platteville bedrock formation is composed of fine-grained limestone containing thin partings of shale and underlain by a thin layer of green, sandy shale of the Glenwood Formation. These formations range in thickness between 5 and 30 feet. St. Peter Sandstone St. Peter Sandstone is composed of fine-to medium-grained quartz sandstone towards the upper half of the layer and multi-colored beds of mudstone, siltstone, and shale with very course sandstone embedded within. This layer's average thickness is about 150 feet. Prairie du Chien Group This bedrock unit is a dolomite that tends to vary a great deal in thickness because its top layer is highly erodible. However, its average thickness is about 120 feet. Golden Valley Natural Resources Management Plan 2015 Background Page 11 Surficial Geology As with most of Minnesota, the Golden Valley landscape was formed by continental glaciers that covered large portions of Minnesota through multiple advances and retreats. . The movement of the advancing glaciers, followed by periods of melting, create a topography of gently rolling to steep hills, wetlands, and lakes. The glaciers are named by the various lobes, and the extent that they advanced. Golden Valley includes material left behind from the Des Moines and Grantsburg advances. Holocene deposits are those that formed after the glaciers had retreated, and include accumulation of organic material in extensive wetlands, and material placed by flowing water. The surficial deposits associated with the most recent glacial and post glacial periods are identified in Figure 2.2. Figure 2.2: Surficial Geology 1fLegend Grantsburg$ i.obe IIMIM Oty or GoNen vatby pmts .O:t:Conp�• .i Geomorphology Class 11111 RAN wnagacw DA caror > . * um Heeg 511 n,,,C.t.co.... III Wen WX. Ibbsene _ Des Moines Lobe °Nome Oep«,n tRY%OubmshMIL.e+e�Peat_Roonp Outwash Fk,via.SeOmerts * r ' 1W .. - _..,, (__ , q Golden Valley Natural Resources Management Plan 2015 Background Page 12 Slopes Identifying steep slopes within the city are important because they typically limit the amount, type, and location of development. However, they also provide opportunities for open space conservation and wildlife habitat enhancement, as this may be the most suitable land use for areas that are too steep to be developed. Golden Valley is predominantly characterized by slopes ranging between 2 to 12%(Figure 2.3). The steepest slopes (18-30%) occur primarily on the eastern edge of the city with a larger area concentration near the northeast corner just north and east of Mary Hills Nature Area. The only area on the west side of the city with steep slopes is located just south of General Mills Research Nature Area. Figure 2.3: Slopes Legend —,q d tmn very'—. SSUROO Sele 6 R•D.elen4SW pep e o_ne ,.,___] 1 6% 'I"'6 .n ::-t6x e _ e • 1 1..e g ,i il 4 '''' ?'' ) t ''mir. -: S AN r../ .S, = ,� .� f A\I.r 17 1 ., 1 C Soils and Soil Textures Approximately half of the soils within the City are mapped as Urban Land, which indicates that it has been disturbed through cut and fill activities, or has been replaced with other material and is Golden Valley Natural Resources Management Plan 2015 Background Page 13 not the soil that originally formed in that location. Where native soils remain, they tend to be composed of loam (an equal mixture of sands, silts, and clays) or coarser material (sandy loam, loamy sand, and loamy fine sand). This reflects the glacial origination of the soils, and the subsequent deposition of materials following glacial retreat. Muck soils are present along historic waterways and older wetland complexes. Figure 2.4: Soil Texture Legend -0 & �,u-:.,;.. Imo ca of Golden Valet'Units .1 e�Jl i:" SSUROO SOIL-TEXTURE DESCRIPTION 'Ali. 3•_3=moi . Loam Sndi loam * Ell1II- r -LDarry fne sa,C mg Sr,'flat loam 4 ;_ y' —Loam/sand Uban Land I Uddllner/s . - ' ggig Muck SSI-RGO Wale, 4F+. 3"� gill -.,. A.„ q43,,4 33,-,,,A calk r.r ..1 r laI t� �l c Lf £ z tP LLP Si�9 . �.� - 4 ---- ..,_,..' ,,,,,i,• ,- , qk Ili�;: `tn 1- fee :. . _ . ,._ i ...„1, , 1 , i i 141117 L ,41% a 4., . c:-. , ..___,,,..._ , ,:. ,,, •,-- ,z„IF:,4 __- �.. . -— I a t.` �a= J IA- �` ) `,1 1 i :1'1, Golden Valley Natural Resources Management Plan 2015 Background Page 14 Hydrology Watersheds and Surficial Hydrology The primary waterway within Golden Valley is Bassett Creek, which has a large watershed encompassing more than 40 square miles within the cities of Crystal, Golden Valley, Medicine Lake, Minneapolis, Minnetonka, New Hope, Plymouth, Robbinsdale and St. Louis Park. The Bassett Creek watershed includes the main branch of Bassett Creek,which originates at the outlet of Medicine Lake, and the Sweeney Lake branch of Bassett Creek,which flows through Sweeney Lake, and joins the main stem within Theodore Wirth Park(Figure 2.5). In a small portion of the city, generally located so4�sast of 1394 and Highway 100, is a 93 acre I1, area that is part of the Minnehaha Creek watershed.Both Bassett Creek and Minnehaha Creek drain into the Mississippi River. Golden Valley's water resources include Bassett Craelc sklaffer streams and tares to Bassett Creek, Sweeney, Twin, and Wirth Lakes, and wetlands (Figure 2.5). Floodplains are importaoheical features, as they are the primary interface between the aquatic and terrestri. ' dats. dplains tend,frjt seasonal wetlands, and areas that are protected from develosr rnt and 40spachment,Sla they allow a safe place for seasonal flooding, which protects Ito- ;Cs - es, andbifrastructure. Floodplains are based on the s %atad elevation of exp:''.,-t to occur within a`defined frequency of occurrence. From a regulatory standpoint, flopdplains a defined as the elevation of water for precipitation events to occur on a frequency of every,400 :000 years. These two designated floodplains have been identified on ROT 2.5 *ti r Golden Valley Natural Resources Management Plan 2015 Background Page 15 Figure 2.5: Watersheds, Water Resources, and floodplains (still need to show floodplain &wetlands here) - Legend Watershed Name g � i Lake blame, .,:m Meaain,Lake v.^.neaena Creek 7 an Creek Moos Z S 169 e w -- ..........=4....." . _ -- Pre-European settlement Vegetative Prior to European settlement, native prairie, oak woodlands and savannas, marshes, floodplain forests, and woodlands were the dominant plant communities in Golden Valley. After settlement, and prior to the establishment of the City Charter, the majority of the landscape was cultivated farmland and open fields, with remnant wetland and wet prairies (Figure 2.6). At the scale these maps were made, smaller lakes were generally not included, although Sweeney, Twin, and Wirth lakes were certainly present historically. Golden Valley Natural Resources Management Plan 2015 Background Page 16 Figure 2.6 Pre-European Settlement Land Cover Legend I ts.= •.-.,ic,n V,tI v1.rnrts Presettlement Vegetation .-,... a-- ....uak maple. oasswaoo.rackory)/ -Lakes(open water) —Oak openngs ana barrens _Net Pone ,1,.1:?-4,11, .lira • y,<1:.. ' :y.Y '.' : ___ 1 ea 4 ( r p fA Table 2.1 shows a breakdown of land cover types by total acres and percent. Historically, the land was primarily covered by oak openings and barrens with remnants of Big Woods and Wet Prairie land covers. Table 2.1 Distribution of Land Cover Acres Pre European Vegetation Acres Percent of Total Oak openings and barrens 5,377 80% Wet Prairie 921 13% Lakes(open water) 304 5% Big Woods- Hardwoods(oak, maple, basswood, hickory) 145 2% TOTAL ACRES 6,747 100% Golden Valley Natural Resources Management Plan 2015 Background Page 17 Wildlife The City of Golden Valley lies in a region of historic suburban growth and is a mature first ring suburb. The city contains a mixture of primarily single family residential development, in conjunction with concentrations of retail, industrial, and corporate offices. Open spaces and nature areas are present throughout the community, and much like the lots and boulevards, are dominated by mature trees. The City of Golden Valley provides great opportunity for watching wildlife. Common animals that can be seen in Golden Valley are typical urban species,including numerous songbirds, small mammals, deer, and fish. Species such as deer,tanada geese,Waterfowl, squirrels, rabbits, coyote, raccoons, turkey, and skunks have increased in this area since:these animals do well around moderate human development. Other species have declined for the same reasons. Management recommendations for wildlife in the cityare provided below. In general, appropriate management of the open spaces will help improve populations of desirable native animals and improve citizen relationships with wildlife in general.Wildlife can become nuisance, when they are overpopulated,or degrade the natural areas or property. Education on wildlife, and management isessential for positive results., The Natural Heritage Information System database is used by the state of Minnesota to track occurrences of rare plants and animals, and unique or critical habitats. Within Golden Valley, a tamarack swamp located in Theodore Wirth Park Is identified,for example. Occurrences of rare plants haveoccurred, but theonly recent occurrence is that of dwarf trout lilies which are transplanted individuals located within the Wirth Park. Rare animals have been observed, including trumpeter swans(Cygnus buccinator), Blanding's turtle (Emydoidea blandingil), and bullfrog (Lithobates catesbeianus),which have been observed in the aquatic habitats near Wirth Park. Peregrine falcons(Falco peregrinus) have been observed within Golden Valley, although they do not nest within the city limits. Preservation of high quality natural areas will provide spaces for wildlife, which in turn provides opportunities for residents to observe wildlife. A positive correlation exists between the size and quality of the habitat, and the populations and quality of the associated wildlife. Golden Valley Natural Resources Management Plan 2015 Background Page 18