MVID Instream Flow Improvement Project (MIFIP) Project Description

Version 8:  updated Aug. 4, 2014
(This description will be updated periodically as new information becomes available)

Project Elements:

The project consists of three elements:  the MVID West Pump System, the MVID East Canal Pipe, and Well Conversions.  See Figure 1 for an overview of the entire project area by element.

West Pump System

The MVID West Canal system will be replaced by the West Pump System, which will consist of a pressurized pipe/pump system designed to serve approximately 73 parcels within and surrounding the Twisp town boundaries. It will be supplied by a well field comprised of up to four, small groundwater wells located near Hank’s Market.  The wells will be interconnected via a pump manifold to provide pumping redundancy, allow more flexibility in matching water delivery to changing demand, and allow maintenance of the pumps by locally available resources.  Maximum operating pressure at the high point of the system of the system will be at the discretion of the Directors up to the design pressure of 10 psi.  Pressures at the lower (southerly) end of the system will be controlled by well field pump settings and pressure reducing devices as needed.

The proposed pipeline route will be westerly from the well field behind Hank’s to the Twisp-Carlton Road, where it will divide into to the two following proposed routes (See Figure 2): 

  • A pipeline serving the north end of the system will cross underneath the Twisp-Carlton County Road up to the existing MVID West Canal through Painters Addition and will then follow the alignment of the existing canal in a generally NW direction to the end of pipe in the vicinity of Lookout Mountain Road.  
  • A pipeline serving the south end of the system will parallel the Twisp-Carlton Road south to a road crossing near the Church of Jesus Christ of Latter Day Saints.  After crossing under the road, it will travel uphill in several branches to serve members down to and including the Jolley property.

Total West Pump System mainline pipe length will be approximately 9,700 feet.  Pipe diameters will range from 15” to 3” and will be either HDPE or PVC.  Existing West Pump System laterals will be evaluated and replaced and relocated as needed as part of this project.

West Side decommissioned canal: The canal from the existing Twisp River intake down to the north end of the pressurized pipe system (2.9 mi.) and the canal below the south end of the pressurized pipe system (5.9 mi.) will be decommissioned.  The decommissioned sections of the canal will not be re-contoured.  Members with parcels in the decommissioned sections will be converted to wells.

East Canal Pipe

The MVID East Canal will be partially replaced by a piped system beginning at or near Mill Hill and extending down the existing canal alignment to a drain at Beaver Creek.  This gravity-pressurized system will supply approximately 253 parcels east of the Methow River, including some lots within the Town of Twisp.  A portion of the MVID canal north of Mill Hill is used by MVID under a contract with the Barkley Irrigation Company (BIC).  If the BIC decides to pipe its canal down to Mill Hill, it is possible that the East Canal pipe will later be extended upstream.  To allow for this possibility, the pipe will be designed to accommodate the higher pressures that would result.  Static pressures in the main pipe will range from zero at Mill Hill to 36 psi at Beaver Creek.  Pressures will be approximately 8-11 psi higher if the pipe is extended above Mill Hill to the existing Methow River headgate.

Total mainline pipe length will be approximately 27,050 feet.  Pipe material will be HDPE or PVC and will range from 24” at Mill Hill to 10” at Beaver Creek.

E-1 Lateral System:  MVID members located within the Town presently served or potentially served by the E-1 lateral system will remain within the MVID and be served by the new East Canal Pipe.

E2-E5 & E13 Lateral Systems:  Ecology-funded laterals installed in 2005 will not be replaced.  They will be leak-tested and repaired as needed. 

All remaining lateral systems: (E6 – E11) will be evaluated and replaced and relocated as needed as part of this project.  The trestle at Beaver Creek will be abandoned and removed.  Drains and isolation valves will be installed at the existing Mill Hill Spill, Loup Spill and Beaver Creek.

East Side decommissioned canal: The canal south of the end of pipe at Beaver Creek will be decommissioned (approx. 1.9 mi).  Projected last date for the canal to run water is October 1 2014.  The new East Canal Pipe will be completed from Mill Hill opposite Twisp to Beaver Creek by May 1, 2015.  Members below Beaver Creek will receive their water from individual wells.

Well Conversions

Considering both the West and East Sides, approximately 85 parcels may be converted to individual wells, assuming one well per group of contiguous parcels under common ownership.  Converted parcels may be excluded or retained within the District at MVID’s discretion.  (See Figure 1 for the areas to be converted to wells.)

MVID members converted to individual wells who demonstrate to MVID the ability to put the water to beneficial use will be compensated for well construction under a plan being developed by the Project Team.

Risks to landowners from tree mortality and stormwater drainage

Risks to landowners from tree mortality along both the piped and decommissioned canal sections (East and West) will be evaluated in 2014. 

  • In piped sections of the canals, all trees impeding pipe installation will be removed for 8’ on either side of the existing canal.  For these piped sections, MVID members and non-members across whose land MVID holds an easement or right-of-way will be offered a one-time chance to indicate which trees they wish to retain if they sign a liability release for the trees.  All other trees in the piped sections deemed hazardous by MVID will be removed from the MVID right-of-way.  Non-hazardous trees in piped sections will remain at MVID’s discretion.  In response to a written landowner request, tree removal outside the MVID right-of-way in piped sections will be considered on a case-by-case basis. 
  • A similar hazard tree removal policy for decommissioned canal sections is being considered by the Directors.

The proposed piped and decommissioned canal sections (East and West) were evaluated in 2013 for potential failures caused by ephemeral and stormwater drainage.  These risks will be addressed as part of this project by such measures as leaving existing spills functional and providing drains and diversion berms to route water away from the installed pipes into existing drainages.  If necessary, after tree removal, the decommissioned canal will be cleared to allow drainage to the spills.