Estler Lake Dam Rehabilitation Allied Engineering Services, Inc. Montana Association of Dam and Canal Systems Estler Lake Dam Rehabilitation October 19, 2016 Presented by: Koy Holland Paul Sanford, MSCE, PE, CFM

Presentation Outline Pre-Project Condition Goals & Objectives Rehabilitation Components Design Process Project Implementation Post-Construction Monitoring Owner’s Perspective Questions and Answers Allied Engineering Services, Inc.

Project Collaborators Owner: Rattlesnake Reservoir & Water Company Review Agencies DNRC: Michele Lemieux, PE; John Connors, PE USFS: Scot Shuler; Mark Libby; Kyle Schmitt Consultant: Allied Engineering Contractor: RE Miller and Sons, Inc. Landowner: USFS Funding Agency: DNRC Allied Engineering Services, Inc.

Vicinity Map 19.5 miles NW of Dillon Beaverhead NF Southern end of East Pioneer Mountain Range Elevation over 7,800 feet Staging area 1.1 miles downstream of Kelley Reservoir 3.8 miles from Kelley to Estler via ATV trail Allied Engineering Services, Inc.

Site Map Allied Engineering Services, Inc.

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Rehabilitation Summary Allied Engineering Services, Inc.

Project Description: Pre-Project Condition Dam constructed in 1903 Between 1903 and 1963 – minor repairs 1963 – dam reconstructed Replacement of existing outlet controls Upstream extension of low level outlet Reconstruction of the upstream face of dam On-stream (Estler Creek) storage reservoir Earthen embankment roughly 330 feet long Height of 35 feet Allied Engineering Services, Inc.

Project Description: Pre-Project Condition Normal storage volume of 470 acre-feet Low-level outlet 40-ft section of 24-inch CMP (upstream end) 79-ft section of 24-inch wide x 36-inch tall concrete arch pipe Inclined slide gate controlled by hand-wheel on crest of dam Principal spillway Rock channel on left abutment 2.9 feet freeboard from crest to low point on the top of embankment 15-feet wide No emergency spillway Allied Engineering Services, Inc.

Project Description: Pre-Project Condition Downstream Embankment Lower course (~14.6 vertical feet) – near vertical stacked rock Second course (~7.6 vertical feet) – grouted rock ~1H:1V Third course (~6.0 vertical feet) – stacked rock, ~0.8H:1V Upper portion – earth, 2H:1V Allied Engineering Services, Inc.

Project Description: Pre-Project Condition Concrete arch low-level outlet pipe and downstream embankment (stacked rock wall). Allied Engineering Services, Inc.

Project Description: Pre-Project Condition Principal spillway – lined with rock and some steel slip scrapers Allied Engineering Services, Inc.

Project Description: Pre-Project Condition Downstream embankment Allied Engineering Services, Inc.

Project Description: Problems Photo courtesy of MT DNRC Project Description: Problems 1. Low-level outlet reaching end of design life. 2. Inclined gate difficult to operate and did not seal properly. 2. Limited freeboard and no emergency spillway. 3. Downstream embankment susceptible to deformations during seismic activity. Allied Engineering Services, Inc.

Project Description: Goals & Objectives Provide reliable water storage and delivery for another 100 years Agricultural preservation Provide increased ease of operation Minimize maintenance Objectives Rehabilitate the low-level outlet Stabilize the embankment Construct an emergency spillway Allied Engineering Services, Inc.

Project Description: Rehabilitation Components 3 Primary Components: Low-level outlet; embankment; emergency spillway Allied Engineering Services, Inc.

Components: Low-level outlet Components (downstream to upstream) Concrete encased 18-inch HDPE: 28 feet Slipline concrete arch with 18-inch HDPE: 81 feet Reinforced concrete pressure pipe (18-inch): 54 feet Allied Engineering Services, Inc.

Components: Low-level outlet Components (downstream to upstream) Concrete encased 18-inch HDPE: 28 feet Slipline concrete arch with 18-inch HDPE: 81 feet Reinforced concrete pressure pipe (18-inch): 54 feet Allied Engineering Services, Inc.

Components: Low-level outlet Components (downstream to upstream) Concrete encased 18-inch HDPE: 28 feet Slipline concrete arch with 18-inch HDPE: 81 feet Reinforced concrete pressure pipe (18-inch): 54 feet Allied Engineering Services, Inc.

Components: Embankment Toe Drain Diaphragm filter Rock fill on downstream face Raise embankment 1.2 feet Flatten upstream face at low-level outlet Allied Engineering Services, Inc.

Components: Embankment Toe Drain Diaphragm filter Rock fill on downstream face, 1.5H:1V Raise embankment 1.2 feet Flatten upstream face at low-level outlet Allied Engineering Services, Inc.

Components: Embankment Toe Drain Diaphragm filter Rock fill on downstream face, 1.5H:1V Raise embankment 1.2 feet Flatten upstream face at low-level outlet Allied Engineering Services, Inc.

Components: Embankment Toe Drain Diaphragm filter Rock fill on downstream face, 1.5H:1V Raise embankment 1.2 feet Flatten upstream face at low-level outlet Allied Engineering Services, Inc.

Components: Emergency spillway 14-feet wide Crest elevation 2-ft above principal spillway Activated at 50-year and greater flows 2-feet freeboard Allied Engineering Services, Inc.

Design Process Inspection and Topographic Survey: July 2013 Reservoir full during inspection & survey Feasibility Study: February 2015 Design & Permitting: May – September 2015 Allied Engineering Services, Inc.

Project Implementation Construction completed November 2015 Construction Phases Demolition Sliplining Toe Drain & diaphragm filter RCP Pressure Pipe Upstream notch backfill and outlet tower Downstream rock fill Allied Engineering Services, Inc.

Project Implementation: Demolition Allied Engineering Services, Inc.

Project Implementation: Sliplining Cellular concrete (cement, water, foaming agent) – lighter than cement grout, flowable. Dewatering Allied Engineering Services, Inc.

Project Implementation: Toe Drain & Diaphragm Filter Allied Engineering Services, Inc.

Project Implementation: RCP Pressure Pipe 18-inch pressure pipe Concrete cradle Select backfill Allied Engineering Services, Inc.

Project Implementation: Upstream Notch Backfill & Outlet Tower Allied Engineering Services, Inc.

Project Implementation: Downstream Rock Fill Allied Engineering Services, Inc.

Project Implementation: Challenges Elevation, access, schedule. Allied Engineering Services, Inc.

Post-Construction Monitoring & Performance Fill Inspections: January, March, May, and July of 2016 Photo courtesy of DNRC Allied Engineering Services, Inc.

Owner’s Perspective The Big Picture! Image courtesy of Zoetis Allied Engineering Services, Inc.

Owner’s Perspective Funding & Cost Summary DNRC Private Water Grant: $5k DNRC Water Development Loan: $400k Project Cost: ~$450k Allied Engineering Services, Inc.

Owner’s Perspective Recap of Steps Taken Not a bad setting to work in! Allied Engineering Services, Inc.

Questions and Answers Not a bad setting to work in! Allied Engineering Services, Inc.