TO WHOM IT MAY CONCERN: This notice is issued in accordance with the Compensatory Mitigation for Losses of Aquatic Resources; Final Rule (the Mitigation Rule) described in the Federal Register dated April 10, 2008 (33 CFR Parts 325 and 332). The St. Louis District and Rock Island District share the Central Plains/Cuivre/Salt Ecological Drainage Unit Service Area for this bank proposal and therefore will be requesting comments from both areas of responsibility. This service area will provide mitigation options for applicants in both Districts.
Project Location: The proposed site is located within Section 26, Township 63 North, Range, 7 East Lewis County, Missouri. Latitude: 40.225199, Longitude: -91.640912. (See attached location maps).
Bank Objectives: The fundamental objective of compensatory mitigation is to offset aquatic resource losses resulting from unavoidable impacts to waters of the United States authorized by Department of Army Permits, through the means of selling stream and wetland mitigation credits for projects developed by other entities. The main goals of the project include in-stream and riparian buffer restoration, and restoration and enhancement of wetland and upland buffer areas.
Project Description/Bank Establishment: The Sponsor (Sunflower Enterprise) has submitted the Lewis County Stream and Wetland Mitigation Bank prospectus, which proposes two alternative mitigation bank options/concepts. Concept A is approximately 174 acres and Concept B is approximately 146 acres. The reason for two alternate options is due to the presence of an overhead powerline (OHL) near the western edge of the site and its potential impact on restoration, construction, and credit generation.
- The presence of mapped hydric soils, surface water in existing wetlands, high groundwater tables, and man-made drainage structures indicate that wetland hydrology can be restored permanently. Groundwater monitoring wells will be installed in 2025 to evaluate seasonal changes in groundwater levels. Both design concepts operate on similar principles: capture drainages from adjacent upland areas to the east and pool water in a series of wetland cells created through shallow excavation and creation of wide and low berms. Microtopography will be utilized within the restored wetland areas to maximize the flow path and add diverse wetland depths. Unless otherwise noted in the construction plans, any ditches or subsurface drainage tiles within the Bank will be plugged to help restore wetland hydrology.
- Wetland enhancement will primarily be achieved through plugging of ditches and stream restoration (see below) to restore wetland hydrology. In wooded wetland areas, Timber Stand Improvement (TSI) will be employed to encourage the growth of slower growing hard mast producing trees, such as oaks, and increase the overall diversity of plant species. In these areas creation of “berm and pool” complexes will be utilized in select locations in order to create more diverse wetland habitat. A “berm and pool” complex uses selective grading to excavate a shallow pool, which mimics a vernal pool and/or oxbow. The excess spoil is placed adjacent to the pool, elevating the existing ground surface 0.5-1 foot and providing a suitable location for planting trees.
- Two tributaries, located in the northwest corner of the Bank, are potential candidates for stream restoration (labeled “st-03 and st-04”). St-03 feeds into St-04, which flows directly into the Wyaconda River. These stream reaches are channelized, incised, and lack a meaningful hydrologic connection with the adjacent floodplain. To restore the streams, low-tech process-based restoration techniques are proposed. These methods include installation of Beaver Dam Analogs (BDA’s) within the channels to slow stream flows, increase groundwater recharge, enhance water storage in the adjacent floodplain wetlands, promote sedimentation within the channel to raise the streambed, and create complex channel morphology and habitat diversity. These low impact methods will reduce negative effects to the surrounding woodland normally associated with stream restoration projects. The goal is for the system to become selfsustaining:
beaver sign is evident throughout the forested portions of the bank – these structures would jumpstart their ecosystem engineering process.
Service Area: The proposed primary bank service area will be the Central Plains/Cuivre/Salt Ecological Drainage Unit - Service Area, which includes the St. Louis and Rock Island District.
Click the link below to view the full notice.