Wetland Compensation Plan

Transcription

1 Wetland Compensation Plan Prepared for Prairie Mines & Royalty ULC Poplar River Mine North Expansion By Ducks Unlimited Canada May 2014 ducks.ca

2 INTRODUCTION In order to compensate for the wetland hectares lost during mining progression of Pit 8 at Poplar River Mine North Extension, Prairie Mines & Royalty ULC proposes the implementation of a wetland loss compensation plan, prepared by Ducks Unlimited Canada (DUC), to replace wetlands disturbed at an off-site location. In 2013, Stantec prepared a Wetland Impact Evaluation report for the Pit 8 expansion at Poplar River Mine North for the Ministry of Environment (MOE) as per the Draft Ministry of Environment s Wetland Mitigation Guideline: User Handbook. The Stantec report identified a total wetland area of 8.63 original hectares. Using the wetland debit calculation, outlined in the above mentioned Mitigation Guidelines, this area computes to service hectares (see table 1). DUC used the wetland credit calculation, from the same Mitigation Guidelines, to compute offset hectares being required to replace the identified debit service hectares. An off-site restoration/compensation plan will require the submission of a change in development, in order to meet our conditional approval pursuant to Section 16(2)(a) of the Environmental Assessment Act, EAB File # and EAB File # This compensation plan will serve as the Change in Development submission. COMPENSATION PROPOSAL Wetland Compensation DUC proposes to be the habitat compensation delivery agent and would address the loss of wetland habitat impacted by the Prairie Mines & Royalty ULC Pit 8 expansion project. The MOE will ultimately provide approval for the compensation plan and will apply a formula based approach to determining debits (wetlands lost) and credits (wetlands restored) described in this proposal. The compensation plan includes all costs associated with: Identifying and sourcing potential lands,assessment of property, reconnaissance and wetland restoration design Land securement negotiations Land purchase costs and subsequent loss incurred when re-selling the property with a perpetual conservation easement (CE) placed on the title Appraisals and legal fees Stewardship costs of acquired land including restoration costs A one-time contribution to a project management fund for the long term/perpetual management and monitoring of the property Professional survey to verify the wetland acres restored for auditing purposes (internally or externally) Wetland Compensation Plan Ducks Unlimited Canada 2

3 Credit Calculation As per the MOE guidelines the following multipliers are being used to determine service credits for potential wetland restoration projects in DUC s Missouri Coteau priority landscape. DUC determined each multiplier below by analyzing six recently purchased quarter sections that had sufficient wetland restoration to satisfy the service hectare debits. Similar multipliers are anticipated for properties secured in within the Missouri Coteau. Wetlands of special concern [M wc ] Multiplier of 1.00 (<50% wetland loss) Ecosystem services [M es ] Multiplier of 1.00 Native upland habitat [M up ] Multiplier of 1.25 (50-75%upland loss) Wetland numbers [M wn ] Multipier of 1.25 (11-49 wetlands) Species of concern [M soc ] Multiplier of 1.00 (no known species of concern) Offset type [M typ ] Multiplier of 1.00 (wetland restoration) Offset permanence [M prm ] 0.80 (perpetual conservation easement) Offset risk [M rsk ] 1.00 (DUC has a proven track record in approach) Service ha debits [S ha ] ha (as determined by Stantec Evaluation) The MOE credit calculation is: S ha = (O ha )(M wc )(M es )(M up )(M wn )(M soc )(M typ )(M prm )(M rsk ) The following calculation determines the required amount of offset hectares (O ha ) required to compensate the service hectares (S ha ). S ha = ha (M wc )(M es) (M up )(M wn )(M soc )(M typ )(M prm )(M rsk ) (1.0)(1.0)(1.25)(1.25)(1.0)(1.0)(0.8)(1.0) = O ha offset hectares (29.7 acres) of restored wetland required (Missouri Coteau landscape) Compensation Program Delivery Options The compensation program will be delivered through DUC securing access to property (often requires the purchase of suitable lands) whereby the wetlands and associated riparian areas are restored. After all restoration activities are complete, DUC would protect the property with a perpetual CE placed on the land title that protects all the restored acres that contribute towards the compensation plan. DUC will seek out these suitable restorable properties but is contingent upon availability of the lands and Willing Seller/Willing Buyer and therefore a time period of five years may be required before land is secured and restored. Every effort will be made to complete the wetland compensation as soon as possible and annual progress reports will be prepared. Once the wetland restoration works are completed, DUC will annually monitor the restored wetlands and the constructed ditch plugs for three years. After the three-year period, the restored wetlands are considered established and inspections will carried out in a one-in-five year time frame. Wetland Compensation Plan Ducks Unlimited Canada 3

4 TABLE 1. DEBIT CALCULATION FOR WETLANDS TO BE DIRECTLY IMPACTED BY PROJECT Wetland ID Land Location Wetland Area (ha) Multiplier Service-hectares (ha) Qtr Sec Twp Rge Mer [Wha] [Mwc] [Mwl] [Mes] [Mwn] [Msoc] Sha Sha N 2 1 SE W SW W N 2 SW W N 3 NE W NW W N 4 NE W N 5 NE W N 6 NW W N 7 SW W N 8 SW W N 9 SW W N 10 SW W N 11 SE W N 12 SW W N 13 SW W N 14 SW W N 15 NE W N 16 NE W N 17 NE W Total Sha The debit calculation for Wetland N 1, which is bisected by a road, was conducted in two parts to take into consideration land use differences between the different quarter sections. Note: S ha =(W ha )(M wc )(M wl )(M es )(M wn )(M soc ) Where [W ha ] is the size of the wetland to be impacted (in hectares) [M wc ] is the wetland of concern multiplier [M wl ] is the wetland loss multiplier [M es ] is the contribution to ecosystem services multiplier [M wn ] is the number of wetlands impacted multiplier [M soc ] is the species of concern multiplier Table prepared by Stantec in the Wetland Impact Evaluation for the Pit 8 Expansion at Poplar River North Mine, dated October 16, Wetland Compensation Plan Ducks Unlimited Canada 4

5 PRIORITY LANDSCAPE Missouri Coteau CACTUS LAKE HILLMOND SASKATCHEWAN Meadow Lake THICKWOOD North Battleford TRAMPING LAKE EAST THICKWOOD Saskatoon DANA HILLS La Ronge Prince Albert PRINCE ALBERT Smeaton Melfort LENORE/PONASS As a science based organization, DUC needs to consider the optimal conservation lands to apply to the compensation actions, which may or may not be in proximity to the Poplar River Mine Expansion Project site. DUC would target restoration activities in North American Waterfowl Management (NAWMP) target landscapes where the lands would add to existing blocks of functioning habitat (left). Some areas of the province are more conducive to locating drained wetlands that allow for restoration than other areas; DUC will deliver and complete the compensation plan where there are the greatest opportunities for success. Every effort will be made to deliver this wetland compensation in the Missouri Coteau priority landscape which is the nearest NAWMP target area to the mine expansion. CONJURING CREEK COTEAU NORTH ALLAN HILLS QUILL SOUTH TOUCHWOOD/BEAVER Yorkton UPPER ASSINIBOINE Melville PHEASANT HILLS FOX VALLEY COTEAU CENTRAL REGINA EAST Regina VIRDEN/SASK Weyburn COTEAU SOUTH LIGHTNING BOUNDARY PLATEAU Estevan Missouri Coteau Priority Landscape Wetland Compensation Plan Ducks Unlimited Canada 5

6 Typical ditch plug construction. Aerial view of newly constructed ditch plugs. DITCH PLUG CONSTRUCTION The first component to restoring a landscape s health is to restore its hydrological function. This can be done by plugging existing ditches and recontouring areas back to their natural wetland shape. In very short time, Mother Nature takes over, the wetland refills through natural runoff, and plants and animals return to the wetland. Restored wetland after 1 year. Restored Wetland after 3 years. Wetland Compensation Plan Ducks Unlimited Canada 6

7 Appendix A. How to Restore a Prairie Wetland Typical prairie wetlands are the easiest types of wetlands to restore. The wetland can simply be restored by re-contouring (ditch plugging) part of the drainage ditch back to the original ground level to restore water retention. This is the most cost effective method that uses on site soil material to re-contour the drainage area to pre-drainage conditions. Once a drained wetland site has been identified through the use of air photos, satellite imagery and/or topographic maps, a field visit is required to identify the location of the ditch plug and if there is any need for a survey. A survey may be required if the restored wetland may possibly flood a neighboring landowner or road. Adjusting the plug height is critical to keeping the water within the natural confines of the wetland basin, so a survey can help in understanding what height to build the ditch plug and exactly what area will be flooded. Once the field visit and survey (if required) is complete, a contractor is hired to start moving dirt. First, the topsoil is removed from the ditch and high ground area and stockpiled for later use. Using dirt from the high ground, the ditch is filled in and the ground re-contoured to natural levels. The ditch is filled in from the edge of the wetland back along the ditch at a 10:1 slope. The topsoil is then spread over the filled ditch and disturbed ground and seeded with a grass legume mix. Seed is broadcast on the site and then followed by a harrow to promote seed contact with the soil. topsoil mineral soil srtipped topsoil Step A Strip topsoil from ditch and high ground area and stock pile for later. natural or historic water level of drained basin ditch Step C Recontour fill downstream. high ground Strip topsoil from ditch and high ground area use dirt from high ground for fill Step B Using dirt from high ground, fill in the ditch to restore the wetland bank and recontour the ground to natural level. stock pile topsoil water water level bottom of ditch fill in ditch from edge of wetland back along ditch at 10:1 slope. bottom of ditch (to be filled) Step D Spread the topsoil back over the filled ditch and disturbed ground and seed the area with a grass legume mix. Replace topsoil and seed with a grass legume mix Plugs are typically built in the fall so that the basin can catch water from the spring snow melt in the following year. Inspection of the plug would take place the following spring or summer to make sure that vegetation is growing on the plug and no erosion has taken place on the plug. If necessary, repairs and re-seeding would be completed in the fall. If the land around the restored wetlands is cultivated, this land would be seeded with a forage seed mix. A meadow brome and alfalfa seed mix is often used with avoidance of invasive species like smooth brome. After the ditch plug is constructed and the basin begins to collect water, most restored wetlands will develop emergent and submersed aquatic vegetation within the first few years. A GIS sketch plan is drawn for each property, where each ditch plug would be identified with a GPS location. The number of flooded acres are identified for each quarter section and recorded on the sketch plan. Other land features on the properties such as trees and seeded uplands are also identified and included in the sketch plan. Appendix Ducks Unlimited Canada 7