rusty gibson: what if the lakes go dry, twca fall conference 2015

What if the lakes go dry?

The Emergency $130-Million Ward County

Water Supply Project

Texas Water Conservation Association

Freese and Nichols, Inc.Rusty Gibson, P.E.Nick Lester, P.E.

Colorado River Municipal Water District

John GrantCole Walker, P.E.

Ward County Water Supply Project


• Project need• Project schedule• Permitting• Construction manager-at-risk• Alternate procurement method - CSP• On-site mixed controlled low strength

material• Trench excavated embedment material• Summary and conclusions

INTRODUCTION


CRMWD SYSTEM• District provides water

for Big Spring, Odessa, Snyder, Midland, San Angelo, Stanton, Robert Lee, Grandfalls, Pyote and Abilene

• Serves 25 counties and 500,000 people in West Texas

• Current demands about 70 MGD


CRMWD SYSTEM MAP


RESERVOIR COMBINED CAPACITIES

Thomas, Spence and Ivie Reservoirs


2011 HEAT AND DROUGHT

http://blog.chron.com/climateabyss/files/2011/09/Txmayaug.gif


Lowest Level77,000Ac-ft(6%)

Full1.2

million Ac-ft

BEFORE AND AFTER THE DROUGHT


LAKE SPENCE INTAKE STRUCTURE


WATER DEMANDS WERE UP


WARD COUNTY WATER RIGHTS


NEW WARD COUNTY SYSTEM

• Well Field– 21 new wells– 20 miles of well field piping– Well Field Booster Pump Station

• One transmission pump station (30 MGD)• 45 miles of 48- and 42-inch pipeline• Pump station at Odessa Reservoir (25 MGD)• New Big Spring Pump Station• Piping modification at Terminal Reservoir



SOURCES OF PROJECT FUNDING• Texas Water Development Board– State Participation Account–Water Infrastructure Fund

• Open Market Financing • CRMWD Contingency & Improvement

Fund



SCHEDULE AND CONTRACT STRUCTURE


DESIGN EXPEDITION• Design ideas to

expedite schedule– Aerial survey– Multiple teams: survey,

easements, SUE, design– Multiple equipment and

design packages– Pump station contracts

split into Below Slab and Above Slab Packages



SCHEDULE/COST SAVINGS

• Eliminate intermediate pump station with larger diameter transmission pipeline to save $6 million and allow higher capacity



• Design ideas to expedite schedule– Native embedment

material for pipelines– Use local concrete mix

design– Modified equipment

specifications (pre/post submittal meeting, materials, testing)

– On-site mixed controlled low strength material (CLSM)

CONSTRUCTION EXPEDITION



• Ideas to expedite permitting – Environmentalist

reviews to help pick route

– Multiple archeological teams

– Route avoided USACE 404 permit triggers

– Special measures to protect the threatened Sand Dune Lizard

PERMIT EXPEDITION



• Ideas to Expedite Land Acquisition – Route along existing pipeline/utility

corridors and roads– Three survey crews for boundary

surveys– Portions of Pipeline routed in public

streets to decrease number of easements

– Easement acquisition concurrent with bidding and pipe manufacturing/construction mobilization

LAND ACQUISITION EXPEDITION



• Construction ideas to expedite schedule– Two Pipeline packages for transmission

pipeline($3.6 million deduct for winner take all)

– CMAR for pump station construction and long delivery items (pumps, valves and electrical equipment)

– Two well drillers working 24/7– Transmission pipe made in five pipe

plants

CONSTRUCTION EXPEDITION



CONSTRUCTION MANAGER-AT-RISK• Owner hires CMAR to act as general contractor• Design Phase: Design reviews, innovations, and

management of cost and schedule• Construction Phase: Hires vendors, sub-contractors or

self performs construction• GMP established after all packages bid out• Reduces project delivery times – design and

construction can overlap• Owner retains control of design and equipment

selection• Produces fewer change orders



• CMAR packages– Big Spring PS Skid– Big Spring PS Site Construction– Pump and Motor Package– Valve Package– Electrical Package– Slab and Below for TPS, WFPS,

OPS– Above Slab for TPS, WFPS, OPS– Wellhead and Pump

Installation

CONSTRUCTION MANAGER-AT-RISK



• Competitive Sealed Proposals (CSP)– Expedite delivery and increase quality– Value based selection (not price only)– Selection criteria – cost, time,

qualifications, claims history, safety, and equipment performance

– Allows Owners to select Contractors/Vendors that have a record of on-time performance

ALTERNATE PROCUREMENT METHODS



• Transmission Pipeline crossed 4 miles of sand dunes in Monahan's Sand Hills State Park– Up to 30 feet of shifting sand

over pipe– Mobility of equipment was

difficult– Caving trench walls a

concern– Future maintenance and

repair difficult

ON-SITE MIXED CLSM



• Native materials – blow sand with some silts

• Portable batch plant used• CLSM used 2 Bags

Cement/CY• Mix was very flowable• Provided 50 psi strength

at 3 days and 200 psi at 28 days

• 30 CY of CLSM / hour• 500-600 LF of pipe / day

SOLUTION: ON-SITE MIXED CLSM



• Soil Modulus (E’) of 3,000 psi

• Provided side support in caving trench walls

• No delivery of concrete or gravel embedment required

• More robust design should reduce maintenance requirements

• Pipe deflection measurements verified quality

ON-SITE MIXED CLSM



• Native material – Sand and caliche/rock• Saved $5 million versus imported gravel– Material cost– Hauling cost– Disposal cost

• Material screened• Moisture addition is generally required• Material placed in lifts and heavy

compaction

TRENCH EXCAVATED EMBEDMENT MATERIAL



TRENCH EXCAVATED MATERIAL

• Native Material Design– Geotechnical investigations

of soils required– Finite element analysis of

pipe-soil interaction– Specification modifications

for bedding and compaction– Requires skilled contractor– Requires more quality

control testing



• Expedited Construction

• Saved Estimated $1.1 Million

• QC Tests to Verify Quality

WELD AFTER BACKFILL



TRANSMISSION PUMP STATION


ODESSA PUMP STATION


WELL FIELD PUMP STATION


WELLS


PROJECT METRICS• Original Budget

Design and Construction: $135 million

• Actual Budget Design and Construction: $113.1 million

• Schedule: 18 Months Design and Construction (2 weeks early)

• Initial Capacity: 30 MGD (Expandable to 50 MGD)


• Methods to Expedite Schedule

• Benefits of CMAR• Benefits of CSP• On-site Mixed

CLSM• Trench Excavated

Embedment Material

• Weld After Backfill

SUMMARY AND CONCULSION


PROJECT AWARDS


ACKNOWLEDGEMENTS