WETLAND DELINEATION REPORT NORTH MINTURN PUD Eagle County, Colorado prepared for: MINTURN CROSSING, LLC 301 BOULDER ST #309, MINTURN, CO 81645 prepared by: BIRCH ECOLOGY, LLC 429 MAIN STREET, LYONS, CO 80540 BIRCH ECOLOGY SEPTEMBER 2020 TABLE OF CONTENTS Section/Title Page 1.0 INTRODUCTION .................................................................................................................................. 1 2.0 ENVIRONMENTAL SETTING ................................................................................................................ 1 3.0 DELINEATION METHODS .................................................................................................................... 1 4.0 WETLANDS & WATERS OF THE U.S. ................................................................................................... 2 4.1 Game Creek Wetland ................................................................................................................. 2 4.1.1 Location ................................................................................................................................... 2 4.1.2 Vegetation .............................................................................................................................. 2 4.1.2 Classification ........................................................................................................................... 2 4.5.4 Hydrology ................................................................................................................................ 2 4.5.5 Soils ............................................................................................................................................ 2 5.0 ANALYSIS OF JURISDICTIONAL STATUS ........................................................................................... 3 6.0 FIGURES ............................................................................................................................................... 4 7.0 TABLES .................................................................................................................................................. 9 8.0 PHOTOS ............................................................................................................................................. 13 9.0 REFERENCES ...................................................................................................................................... 18 APPENDIX A. FIELD DATA FORMS ....................................................................................................... 19 LIST OF FIGURES Number/Title Page Figure 1. Project Location Map. .......................................................................................................... 5 Figure 2. Aerial Photo. ............................................................................................................................ 6 Figure 3. Wetland Map. ......................................................................................................................... 7 Figure 4. NRCS Soil Map. ....................................................................................................................... 8 LIST OF TABLES Number/Title Page Table 1. Waters of the U.S. Summary................................................................................................. 10 Table 2 . Vascular Plant Species List...................................................................................................... 11 LIST OF PHOTOS Number/Title Page Photo 1. Overview of the riparian wetland corridor of Game Creek. (7/31/20). .................... 14 Photo 2. View of Game Creek downstream of Minturn Road. (7/31/20). ................................ 14 Photo 3. Upland swale between Minturn Road and the Union Pacific Railroad. (7/31/20). .. 15 Photo 4. Willows and reed canarygrass dominate the riparian wetland. (7/31/20). ............. 15 Photo 5. Cow parsnip, largeleaf avens, and leafy bracted aster are common. (7/31/20). 16 Photo 6. Game Creek averages approximately 2 ½-3 feet wide. (7/31/20). ......................... 16 Photo 7. Pit 1 is located on a narrow floodplain inside the wetland boundary. (7/31/20). ... 17 Photo 8. Pit 2 is located in a swale on the upland island. (7/31/20). ......................................... 17 1.0 INTRODUCTION Minturn Crossing, LLC is developing plans for The North Minturn PUD, a residential development consisting of 116 lots to be located on an 18.95-acre parcel in Minturn, Colorado. To aid in project planning, a Wetland Delineation was completed for the project site and two adjacent areas west of Minturn Road, for a total boundary of delineation covering 21 acres. Specifically, the project site is in Section 26 of Township 5 South and Range 81 West in Eagle County (Figures 1 & 2). This report describes the wetlands identified on the project site in terms of their vegetation, soil, and hydrology; provides a Wetland Map; and includes site photographs. Please note, all Figures are included in Section 6.0, Tables are in Section 7.0, and Photos are in Section 8.0. Appendix A contains copies of the field data forms completed during the delineation. 2.0 ENVIRONMENTAL SETTING The North Minturn PUD is an undeveloped site located on a wedge-shaped parcel north of downtown Minturn. The property is located between Minturn Road and Taylor Street, and is bisected by 4th Avenue and 4th Street (Figure 2). The Union Pacific Railroad Right-of-Way and the Eagle River are just west of and approximately parallel to Minturn Road, with U.S. Highway 24 on the west side of the Eagle River. Game Creek, a perennial stream, flows across the northern part of the project site, and continues east to join the Eagle River on the west side of the railroad (Photo 1). North of Game Creek, the parcel climbs up a steep west- southwest facing hillside that vegetated by a mountain shrubland community. Riparian wetlands line Game Creek, and the southern part of the parcel is a disturbed herbaceous community with one isolated stand of non-native peashrubs (Caragana arborescens) along Minturn Road. As shown by Figure 3, the boundary of the delineation also encompasses the lower part of Game Creek between Minturn Road and the railroad (Photo 2), as well as an upland ditch just east of 4th Ave. This ditch seldom flows and it lacks a defined bed and bank, with upland weeds in the bottom (Photo 3). Elevations of the project site range from a high of approximately 8,020 feet in the northeast corner to a low of 7,828 feet near Minturn Road and 4th Avenue. 3.0 DELINEATION METHODS Wetlands were delineated by Heather Houston of Birch Ecology and David Buscher, a Certified Professional Soil Scientist with Buscher Soil & Environmental Consulting, on July 31, 2020. The delineation was conducted in accordance with U.S. Army Corps of Engineers Wetland Delineation Manual (1987) and the Regional Supplement for the Western Mountains, Valleys and Coast (2010). Specifically, wetland boundaries were delineated and flagged based upon the prevalence of hydrophytic vegetation, hydric soils, and indicators of a wetland hydrology. Field forms for the six wetland delineation test pits with vegetation, soils, and hydrology data are included in Appendix A. In general, plant species names follow Weber and Whitmann (1992) with updates from Ackerfield (2015). The wetland status of plants follows the 2019 List for the Intermountain Region. Classification of wetlands follows Cowardin et al. (1979). Wetland flagging was surveyed by Gore Range Surveying of Avon, Colorado. 1 4.0 WETLANDS & WATERS OF THE U.S. Wetlands on the North Minturn PUD project site are illustrated by Figure 4, the Wetland Map, and are summarized in Table 1. 4.1 Game Creek Wetland 4.1.1 Location The Game Creek Wetland covers 15,647 square feet (0.36 acre), with one upland island created by a split-flow channel. 4.1.2 Vegetation Just above Minturn Road, the Game Creek Wetland has a riparian overstory dominated by narrowleaf cottonwood (Populus angustifolia) and balsam poplar (Populus balsamifera) trees, with a few aspen (Populus tremuloides)(Photo 1). Farther upstream, the trees give way to a shrub-dominated community that includes mountain and Drummond willows (Salix monticola; S. drummondiana), redosier dogwood (Cornus serecia), thinleaf alder (Alnus incana ssp. tenuifolia), hawthorn (Crataegus rivularis), snowberry (Symphoricarpos rodundifolius), and serviceberry (Amelanchier alnifolia)(Photo 4). The herbaceous wetland understory is dominated by reed canarygrass (Phalaris arundinacea), an aggressive introduced species. Other introduced grasses including timothy (Phelum pratense), Canada bluegrass (Poa compressa), and redtop (Agrostis alba) are also common along the channel, with orchard grass (Dactylis glomerata), in the shady areas of the understory below the trees. Some of the dominant native forbs include cow parsnip (Heracleum sphondylium ssp. montanum), largeleaf avens (Geum macrophyllum), and leafy bracted aster (Aster foliaceous) (Photo 5). Table 2 lists the vascular plant species observed on the project site during the wetland delineation in July, 2020. 4.1.2 Classification The Game Creek Wetland is in the Palustrine System, with Forested and Scrub-Shrub Wetland Classes, and a Broad-Leaved Deciduous dominance type, according to Cowardin et al. (1979). 4.5.4 Hydrology Perennial stream flows in Game Creek create saturated soil conditions that facilitate wetland development on the banks and floodplain. In addition,