BWPH has compiled a Draft Study Plan based on agency and public consultation and comments to date. A Study Plan presentation meeting will be held on June 14, 2023 at the Hollis Community Building, 35 Town Farm Road, Hollis from 3:00 – 5:00 p.m. BWPH appreciates the Town of Hollis accommodating the meeting.
In support of the Surrender Application and Decommissioning Plan for the Bar Mills Project, Brookfield White Pine Hydro LLC (BWPH), in consultation with the agencies and based on feedback garnered via public outreach, has compiled the following list of resource issues and studies to be conducted in 2022 and 2023. Results will be incorporated into the environmental assessment that accompanies the Surrender Application (Exhibit E).
BWPH requests that any additional study requests be provided in writing by January 4, 2022. Requests may be submitted to BarMills@kleinschmidtgroup.com.
- Geology and Soils
- Sediment Transport – a reconnaissance level investigation of sediment quantity and potential post-breach transport. This study will be conducted in the Winter 2022 – Spring 2023.
- Erosion – an evaluation of post-breach impoundment and downstream conditions regarding potential erosion will be conducted. Shoreline characterization using soil maps evaluated for such properties as K factor, T factor and wind erodibility will be evaluated for the impoundment and areas downstream that may experience higher erosive velocities in the post-removal condition. This study will be conducted in the Winter 2022 – Spring 2023.
- Water Quality and Quantity
- River Elevations – BWPH has completed a river elevation model of the reach from Bar Mills Dam to the upper limit of the existing impoundment just downstream of West Buxton. The results can be found here: https://experience.arcgis.com/experience/0e26d508492e418a95aa7639de8c2ef0/
- Water Quantity – an inventory of existing water withdrawals or discharges in the impoundment will be compiled, including water-supply wells within a defined radius of the impoundment. This will serve as a basis to conceptually evaluate potential effects of lowered water levels in the post-breach condition on ground water elevations in properties and documented wells within the zone of influence. This study will be conducted in the Winter 2022 – Spring 2023.
- Water Quality – an assessment of potential water quality conditions will be evaluated as hydrology transitions from lacustrine to lotic conditions. A metadata review of existing baseline water quality data will be compiled (including prior relicensing studies and ongoing existing water quality monitoring data from the state, SRCC and other sources) and assessed against State parameters for a Class A waters including DO, temperature and E. coli. The compiled data and assessment will be summarized in report form in the Winter 2022 – Spring 2023.
- Resident and Anadromous Species and Habitats – a metadata review of existing baseline fisheries information will be conducted and summarized including from relicensing studies conducted at other assets on the Saco River and a discussion of lacustrine habitat transition. An evaluation of zone of passage for depth and velocity in the vicinity of the proposed breach was completed as part of HEC-RAS modeling of post-breach conditions. This study will be conducted in the Winter 2022 – Spring 2023.
- Tributary Connectivity – a field assessment of zone of passage in water depth and velocities for tributaries to the Bar Mills impoundment under post-breach confluence conditions will be conducted in Spring – Summer 2023. This assessment will include field measurements of impoundment tributaries to determine the location of the first hydraulic control relative to modeled post- breach impoundment elevation.
- Wildlife and Botanical Resources
- Species and Habitats – a metadata review of wildlife species and a reconnaissance level evaluation of existing upland, littoral and riverine habitats will be conducted in Spring 2023 – Summer 2023. This will include field verification of historic characterizations from the prior FERC relicensing via observations by boat.
- Wetlands – A review of US Fish and Wildlife Service (USFWS) mapped wetlands and wetland mapping from the prior relicensing, coupled with a reconnaissance level field verification to establish baseline wetlands conditions in the pre-breach scenario will be conducted in Spring 2023 – Summer 2023. This will include field verification of wetland mapping via observations by boat and assessment of potential effects on wetland connectivity and classification type under post- breach water level.
- Endangered Species – Inquiries to develop a potential state and federal threatened and endangered wildlife and botanical resources list will be conducted using USFWS Information for Planning and Consultation (IPac), and Maine Department of Inland Fisheries and Wildlife (MDIFW) and Maine Natural Areas Program (MNAP) inquiries in Winter 2022. Observations of the presence of listed species and suitable habitats will be recorded during field efforts conducted for the wildlife and wetlands surveys. Should listed botanical species be identified by MNAP, field reconnaissance to confirm presence/absence will be conducted in the Spring – Summer 2023.
- Cultural/Historic Resources
- Cultural Resources – Three pre-European archaeological sites identified as eligible for listing in the National Register of Historic Places are currently managed under BWPH’s Historic Properties Management Plan (HPMP), therefore no additional study is proposed, although BWPH will consult with the State Historic Preservation Officer (SHPO) to determine if adjustment to current management practices may be necessary post-breach. No historic structures are affected by the project currently and are located in upland areas that would be unaffected by post-breach reduction in water elevations.
- Recreation, Land Use and Aesthetics
- Recreation Use and Needs – A summary of existing recreation opportunities within the project impoundment will be provided based upon an assessment of use and needs conducted during the Summer of 2022, including user surveys that indicate an estimate of annual use and an assessment of opinions on crowding and condition at the existing boat launch. An evaluation of conditions in the post-breach scenario will be conducted concurrent with other upland studies in Winter 2022 utilizing the river elevation model of the impoundment.
- Land Use – A modeled assessment of potential additional shoreline lands under the post-breach condition will be conducted in Winter 2022. Hydraulic modeling for the river elevation model of the impoundment will be utilized to quantify additional shoreline lands under modeled water level and river flow conditions. Past land use will also be further considered and evaluated towards informing and planning site specific decommissioning activities
- Aesthetics – An assessment of pre-and post-breach aesthetic conditions in the viewshed including post-breach renderings will be completed in Winter 2022.
The aforementioned studies will be compiled into a Proposed Study Plan to be circulated for agency review and comment during early 2023. BWPH anticipates a 60-day period for agency and stakeholder review of the Proposed Study Plan and an opportunity for additional study requests that address the criteria outlined in 18 CFR Section 5.9(b).