***** Sherriff Creek Trail Closure *****

Below is a copy of an email sent out by Debbie Berthelot regarding the temporary closure of the hiking trails at Sherriff Creek Sanctuary. 

We are planning maintenance at the Milliken Tailings Management Area/Sheriff Creek Sanctuary starting August 4^th .  We will need to close the Sanctuary during the construction period (expected August 5 -11)  in order to minimize interaction between equipment and pedestrians.  Denison has posted a sign at the Sanctuary communicating the planned closure, but we would appreciate the Penokean’s support in communicating the planned closure to club members and other trail users.  I will send a follow-up e-mail to confirm when construction is complete.

Following the Milliken TMA work, we will also be replacing culverts on the Sheriff Lake access roads and will need to close the hiking trails north of the Milliken Mine Road for the period 11 August – 17 August to accommodate construction.  Signs will be posted on the Stanleigh and Lacnor gates during construction.  This work will also require closure of the Stanleigh flying field. Here again Denison will post a sign at the gate communicating the planned closure, but we would appreciate the flying club’s support in communicating the planned closure to club members and other trail users.  Again, I will send a follow-up e-mail to confirm when construction is complete.

The work planned for the Milliken TMA is in keeping with our recent discussions on beaver control and bridge replacement.  Additional rationale and description of the planned work is provided below:

The MPE spillway conveys water from the Milliken TMA to a marsh area that eventually flows into Horne Lake. The Milliken TMA has been used to create a bird sanctuary and public walking trail system that results in high pedestrian traffic through the area. Beaver damming of the MPE spillway has altered the design elevation of the spillway and causes persistent diffi1culties for controlling water elevations at target levels. Removal of beaver debris from this spillway requires considerable effort and trapping efforts are required every year. Heavy beaver damming in one region of the TMA has increased possible washouts of downstream culverts.
This project will involve following items with work locations:

·         Installation of a beaver deceiver at the MPE Spillway to allow testing of this fencing system at decreasing maintenance and improving water management by preventing beavers from damming critical flow structures. A beaver deceiver is a fencing structure that extends out into the water upstream of the inlet, culvert, or spillway which it is protecting. The structure is typically constructed by driving fence posts into the ground in the water and fastening wire mesh to the sides. This type of installation will be impractical at MPE due to the soft material overlying boulders (preventing good post footings) and the depth of the water (preventing work in the water). The plans shown in the attached drawings for MPE will be a modified beaver deceiver constructed of 6x6 6 gauge welded rebar mesh. Fastened to 2” (1/4” wall) square tube steel posts and beams which will be attached to the pedestrian bridge structure. Construction of the fence in this manner is expected to be the most cost effective for installation, require the least maintenance, and be most resistant to ice damage in the winter.

·         Installation of a 2 panel, 16 foot, steel gate at the entrance to the Dam. The gate installation will require removal of the existing gate and removal of material to recess the gate approximately 20 feet from its current location so that equipment and vehicle access is possible. Material will be excavated and mounded on either side of the gate in order to prevent unauthorized vehicle access.

·         Re-establishment of the original elevation of the spillway elevation. An excavator will be used to clear and replace the spillway material at the initial design elevation.

·         Installation of culverts to replace failing and washed out culverts as described below:

o    Culvert 1. 5139866N, 374382E. Replacement of 1 collapsing steel culvert that is 12” diameter and 23’ in length with equivalent size HDPE pipe from RAL inventory. Work is in dry conditions so no water permissions will be required.

o    Culvert 2. 5139732N, 374305E. Replacement of 1 collapsing and eroded steel culvert that is 36” diameter and 18’ in length with HDPE culvert of same dimensions. Work is in water so silt fencing will be used to perform work.

o    Culvert 3. 5139970N, 374348E. Replacement of 2 wooden culverts that are 18” in diameter and 15’ in length with 2 20’ x 14.5” HDPE culverts from RAL inventory. Work is in dry conditions so no water permissions will be required.

·         Replacement of failing bridge structure on site access route. The current bridge timbers have begun to fail and the structure requires replacement. The bridge will be replaced with new lumber with a similar construction design to that existing (will be fit in the field).

·         Installation of beaver baffler at beaver pond. A beaver baffler is a perforated pipe with an obscured inlet area that can be inserted through a beaver dam to control water level regardless of beaver damming activities. This work will use 2 runs of ~75’ x 12” HDPE pipe recovered from RAL inventory that will be installed at the beaver dam to ensure that water levels are lowered and remain at a safe operating level.

Please contact me if you have any questions or require any additional clarification.

Thanks for your support in working with club members and trail users to implement these temporary trail closures to accommodate our maintenance activities.

Kind regards,

Debbie Berthelot