WHITETAIL PLANNED UNIT DEVELOPMENT CONCEPTUAL WETLAND MITIGATION PLAN

Transcription

1 WHITETAIL PLANNED UNIT DEVELOPMENT CONCEPTUAL WETLAND MITIGATION PLAN JUNE, 2017 Prepared for Shore Lodge Whitetail, LLC 501 West Lake Street McCall, Idaho Prepared by Crestline Engineers, Inc. 323 Deinhard Lane, Suite C PO Box 2330 McCall, Idaho (208)

2 WHITETAIL PLANNED UNIT DEVELOPMENT CONCEPTUAL WETLAND MITIGATION PLAN JUNE, 2017 Crestline Engineers, Inc. 323 Deinhard Lane, Suite C PO Box 2330 McCall, Idaho (208)

3 Table of Contents 1.0 INTRODUCTION OBJECTIVES Pollinator Species Wildlife Water Quality SITE SELECTION CRITERIA SITE PROTECTION INSTRUMENTS BASELINE INFORMATION Soils Plants Hydrology CREDIT DETERMINATION METHODOLOGY MITIGATION WORK PLAN MAINTENANCE PLAN ECOLOGICAL PERFORMANCE STANDARDS MONITORING REQUIREMENTS LONG TERM MANAGEMENT PLAN ADAPTIVE MANAGEMENT PLAN FINANCIAL ASSURANCES... 6 Crestline Engineers, Inc. i

4 1.0 INTRODUCTION Crestline Engineers, Inc. (Crestline) was retained by Shore Lodge Whitetail, LLC (Whitetail) to prepare permitting and mitigation plans for impacts to wetlands associated with development projects within the (Whitetail P.U.D.). The project site is approximately 783 acres in size and includes approximately 423 acres of upper slope woodlands, 160 acres of forested rolling hills, and 200 acres of open meadowland. In all, there are approximately 50 acres of jurisdictional wetlands on the property. The mitigation site is located within the McCall Area of Impact west of the City of McCall, Idaho in the S½ of Section 7, Township 18 N, Range 3E as shown on Figure 1, Conceptual Wetland Mitigation Plan. Wetland impact avoidance and minimization was carefully considered during project planning and design and reduced potential wetland impacts 16% to a current proposed impact of 0.84 acres. 2.0 OBJECTIVES The goal of this wetland mitigation plan is to create a practical and regulatory framework for wetland mitigation as compensation for areas that will potentially be impacted as a part of the Whitetail P.U.D Improvements Project. Based on discussions with the U.S. Army Corps of Engineers (USACE) in the spring of 2017, wetland mitigation will consist of the enhancement of portions of palustrine emergent (PEM) wetlands contained within the site with the specific purpose of increasing the quantity of palustrine shrub/scrub (PSS) wetlands, subsequently increasing the vegetative diversity, ecological diversity, water quality, and wildlife habitat in the mitigation areas. Specific mitigation objectives are described in the following subsections. 2.1 Pollinator Species Recent significant declines in bee populations as well as Monarch Butterfly populations have heightened public awareness of the importance of plant species critical to the survival of these insects. The Monarch Butterfly, in particular, is a species that is obligate to Narrow Leaf and Showy Milkweeds for their life cycle and cannot survive without this critical habitat. Therefore, the mitigation plan will include the establishment of a sustainable native species milkweed population as well as other native pollinator species. In addition, while the site contains large areas of PEM wetlands (wet meadows), with healthy populations of flowering hydrophytes, the existing population consists primarily of plants which bloom in the spring/early summer. Therefore, to provide a longer season of pollinators, the mitigation plan will include the establishment of a sustainable population of native flowering forbs which bloom throughout the summer/early fall. 2.2 Wildlife Increasing vegetative diversity will provide numerous benefits to wildlife including the planting of flowering shrubs which will provide food and cover for birds and terrestrial species such as Crestline Engineers, Inc. 1

5 rabbits, deer, and mice and avian predators such as hawks and owls. This will in turn provide opportunities for terrestrial predators such as fox and coyote. Selective plantings of native trees and shrubs will also enhance cover corridors for wildlife movement between areas of cover and open water areas. 2.3 Water Quality The mitigation site includes several small streams flowing through PEM wetland meadows. The lack of shade in these locations allows water temperatures to increase, negatively affecting cool stream fish and benthic macroinvertebrate species. Therefore, the mitigation plan will include the enhancement of riparian habitat by planting shrub and tree species to provide shade along stream corridors. 3.0 SITE SELECTION CRITERIA The siting selected for specific wetland mitigation is driven by the requirement to meet mitigation goals and improving and creating habitat for pollinators and other wildlife. The proposed mitigation site consists of existing wet meadow (PEM) wetlands with several small streams and has a high potential for successful mitigation by enhancing and diversifying vegetative species. This also allows an opportunity create PSS wetlands where PEM wetlands currently exist. 4.0 SITE PROTECTION INSTRUMENTS The proposed location for mitigation is identified on the plat and in the recorded Amended and Restated General Declaration for Whitetail P.U.D. which includes a Wetland Protection Easement stating specifically: All jurisdictional wetlands and designated mitigated wetland areas are identified on the Final Plats for the PUD ( the Protected Areas ). The Protected Areas will be maintained as Open Space for the protection and enhancement of wildlife habitat, riparian functions and values and water quality. Maintenance and preservation of the Protected Areas shall be the responsibility of the Association. In addition to the limitations placed herein on the use of such Protected Areas, by means of their classification as Open Space, the following additional restrictions shall apply: (1) No structures shall be placed on the Protected Areas, except structures necessary to protect and enhance wildlife habitat, riparian functions and values and water quality, and bridges involving no fills into waters of the United States; (2) The Association shall maintain the vegetative cover within the Protected Areas in as natural a condition as practicable, and shall plant only native or native-compatible vegetative species in the Protected Areas; (3) All restrictions and conditions contained in any Permit issued by the Army Corps of Engineers related to the Protected Areas shall be strictly enforced by the Association; and, Crestline Engineers, Inc. 2

6 (4) All of the aforesaid provisions shall apply to Protected Areas, whether the same are contained within platted Open Space parcels or platted lots. 5.0 BASELINE INFORMATION As part of a detailed monitoring plan to be developed for mitigation, a baseline monitoring plan will be prepared to provide information on plant species and their relative densities, soil types, and hydrology. Initial observations include the following. 5.1 Soils The United States Department of Agriculture (USDA), Natural Resources Conservation Service (NRCS) has identified the majority of soils within the wetland area of the site as primarily Blackwell clay loam, a very poorly drained soil, hydrologic group C/D, and listed as hydric on the NRCS Hydric Soils List. Some small areas of the Site may include Archabal loam, 4 to 12 percent slopes, a well-drained soil, hydrologic group B, not listed as a hydric soil, and McCall complex, 5 to 50 percent slopes, a somewhat excessively drained soil, hydrologic soil group A and not listed as a hydric soil. 5.2 Plants Vegetative species observed across the wet meadow areas include, but are not limited to those listed in the following table: 5.3 Hydrology Common Name Mules Ears Rushes Sedges Mountain Geranium American (Western) Bistort Prairie Smoke Scientific Name Wyethea helianthoides Juncus spp. Carex spp. Geranium viscosissimum Polygonum (Bistorta) bistortoides Geum triflorum Camas Camassia quamash White clover Trifolium repens L. Tall Buttercup Ranunculus acris The proposed enhancement areas consist primarily of wet meadow (PEM) wetlands supplied by several small perennial streams. The areas are topographically relatively flat with the water table near the surface and saturation at or near surface. Crestline Engineers, Inc. 3

7 6.0 CREDIT DETERMINATION METHODOLOGY Conceptual Wetland Mitigation Plan The State of Idaho currently relies upon the Montana Method as a means of identifying and categorizing types of compensatory mitigation, and determination of mitigation credits. As discussed in Section 2, the USACE has suggested that wetland enhancement is a logical and acceptable mitigation method for this project. Crestline will coordinate with the USACE on specific mitigation credit ratios and locations within the overall site. Additional specific details will be included in the final mitigation plan. 7.0 MITIGATION WORK PLAN Planting types, methods, and timing are critical for successful establishment of vegetation. Ideally, planting should be conducted in the spring/early summer to take advantage of hydrology and early plant development. However, some seeds such as milkweed and bee plant require exposure to cold temperatures to achieve proper germination in the spring and therefore require fall planting. A planting plan will be developed for the final mitigation plan based on the selected plant types and may include seeds, seedlings, and cuttings. A list of potential vegetative species is included in the table below. A final list of species will be developed after consultation with regulatory agencies and seed/plant suppliers and will include the evaluation of soil and hydrology conditions and recommendations for appropriates species, locations, and planting methods to increase the likelihood of success. Common Name Scientific Name Tree (T), Shrub (S), or Forb (F) Mitigation Benefit Pollinator (P), Bird (B), Water Temperature (T), Late Blooming (L), Wildlife (W) Serviceberry Amelanchier arborea S P, B, W Chokecherry Prunus virginiana T/S P, B, W Snowberry Symphoricarpos albus S P, B, W Bearberry Arctostaphylos uva-ursi S P, B, W Golden Currant Ribes aureum S P, B, W Red Flowering Currant Ribes sanguineum S P, B, W Elderberry Sambucus racemosa S P, B, W Red Twig (Osier) P, B, W Dogwood Cornus sericea S Narrowleaf Milkweed Asclepias fascicularis F P Showy Milkweed Asclepias speciosa F P Rocky Mountain Beeplant Cleome serrulata F P, L Mountain Ash Sorbus americana T/S B, T, W Aspen Populus tremuloides T T, W Blanket Flower Gaillardia grandiflora F P, L Pacific Ninebark physocarpus capitatus S P, B, W Western Spirea Spirea douglasi S P, L, B, W Crestline Engineers, Inc. 4

8 8.0 MAINTENANCE PLAN The final mitigation plan will include a maintenance plan to promote the establishment of viable plant populations and will include the following at a minimum: Control of invasive species Control of undesirable species Control of crowding Replacement planting as needed 9.0 ECOLOGICAL PERFORMANCE STANDARDS Ecological performance standards will be developed in consultation with regulatory agencies and will be based on the use of qualitative and quantitative observations to assess the progression towards meeting plan objectives MONITORING REQUIREMENTS A photographic and vegetative baseline will be established prior to initiation of mitigation activities. Visual monitoring and photo documentation will continue through five growing seasons to determine whether vegetation is establishing in areas and quantities as planned. An annual report will be provided to the USACE by the end of each calendar year during the five year monitoring period following USACE monitoring report guidelines. The annual report will contain a narrative, a list of plant species found in the wetland, and an quantitative and qualitative assessment of the relative health of the vegetation planted for mitigation, and the progress toward mitigation goals. Monitoring per USACE requirements, is typically five years or until goals are achieved and documented LONG TERM MANAGEMENT PLAN The goal in mitigation areas will be for the mitigation vegetation to become self-sustaining and to ensure that adequate measures are taken to protect those areas to promote long-term success of the mitigation efforts. Vegetation should be observed regularly and any invasive or undesirable species should be removed. Seedlings should be monitored closely during the first growing season to ensure that they are not overcrowded by adjacent vegetation. Herbicides should not be used as they can damage desirable vegetation and severely impact aquatic health in streams ADAPTIVE MANAGEMENT PLAN Drought, invasive species, and plant failure are the primary potential failure modes for wetland enhancement at this project. Whitetail maintains a full time staff responsible for landscape management at the Whitetail P.U.D. and golf course. These personnel will be available for responding to upset conditions affecting the mitigation areas. In addition, failure modes will be identified (e.g. vegetative species planted in a location not conducive to their survival) and addressed to reduce the potential for repeat failures. Crestline Engineers, Inc. 5

9 13.0 FINANCIAL ASSURANCES The mitigation areas are located on property owned by Whitetail. Whitetail is an established firm with a long term commitment to the operation of the Whitetail P.U.D. and associated golf course. Financial assurances, if required through the five year monitoring period, can be met by acceptable means such as a letter of credit, escrow account, or other method determined to satisfy regulatory requirements. Crestline Engineers, Inc. 6

10 CRESTLINE E N G I N E E R S NORTH SCALE: 1" = 500' 323 DEINHARD LANE, SUITE C PO BOX 2330 McCALL, IDAHO FAX WHITETAIL PLANNED UNIT DEVELOPMENT CONCEPTUAL WETLAND MITIGATION PLAN PROJECT DATE DRAWN 6/7/2017 FIGURE NO. BJS 1 OF 1