The Ward County Water Supply Project is a finalist in the 2015 ASCE’s Outstanding Civil Engineering Achievement (OCEA) award. Established in 1960, the OCEA Award recognizes a project that makes a significant contribution to both the civil engineering profession and society as a whole.
2011 was the driest and second-hottest year on record in West Texas since the National Climatic Data Center started tracking weather 118 years ago. Soaring temperatures and lack of rainfall contributed to high evaporation, dry soil conditions, and minimal runoff for supply reservoirs. That drought continues to grip much of the western and southwestern U.S., bringing new attention to the nation’s water supplies.
The timing could not have been worse. West Texas in recent years has experienced one of the largest oil and gas booms in decades. This has led to a population boom, with the Odessa and Midland metropolitan areas becoming the second- and third-fastest-growing in the nation.
Facing a water supply crisis, the Colorado River Municipal Water District’s (CRMWD) Ward County Water Supply Project was the emergency solution.
The Ward County project involved the design and construction of 21 groundwater wells, 65 miles of pipeline, and 4 booster pump stations. Designed and constructed in less than 18 months – two weeks ahead of schedule – the $100 million project, which was delivered $25 million under budget, encountered and overcame many engineering challenges. Among them were producing water from an aquifer with highly variable water quality, installing pipelines through several miles of shifting sand dunes, dealing with labor and housing shortages related to the oil and gas boom in West Texas, obtaining environmental permitting, and acquiring easements.
However, the greatest challenge was completing the design and construction in 18 months. Meeting the demanding schedule required 7 design teams, 7 pipe production plants, 7 pipe-laying crews, and 4 construction contractors.
ASCE News Associate Editor Doug Scott interviewed Nick Lester, P.E., M.ASCE, project manager for Freese and Nichols, Inc., the firm that designed and oversaw construction of the well collection and water transmission system.
1. What was the biggest challenge of your project?
This would have been a challenging project under any conditions – our team had to produce water from an aquifer with highly variable water quality, we had to install pipelines through sand dunes, and we dealt with labor shortages because of the oil boom. But our biggest challenge was the schedule. We had to design and construct the whole system in less than 18 months before the reservoirs dried up.
2. What was the most innovative or creative aspect?
There were a lot of innovative aspects, but the most innovative ones were the things we did to meet a tight schedule. We used the Construction Manager-at-Risk (CMAR) delivery method for the pump stations and tanks, which allowed design and construction to overlap. Long-delivery items, such as pumps, valves, and variable-frequency drives, were purchased through the CMAR. We split the pump stations into separate contracts through the CMAR so underground construction could happen while above-ground facilities were still being designed.
We used competitive sealed proposals for CMAR selection and for all equipment and construction contracts; that allowed us to pick contractors and vendors based on their record of finishing projects on time. We also accelerated permitting by avoiding areas where we would have needed an individual 404 permit [refers to Section 404 of the Clean Water Act, administered by the U.S. Army Corps of Engineers], and we accelerated land acquisition by routing the pipeline along existing pipelines and roads as much as possible.
3. Did your project have any technical issues that you had to overcome? If so, what were they and how did you overcome them?
Of all the issues we encountered, the first one that comes to mind is the sand dunes. We had to run 4 miles of the pipeline through shifting sand dunes, which was challenging on several levels. When the dunes shift, they can add as much as 30 feet of fill over the pipeline, and that would exceed the structural capacity of the pipe. Plus, the caving walls of the trenches don’t provide enough side support for the pipe, and it’s difficult for construction equipment and delivery trucks to get through the dunes. Our team solved those challenges by using batched controlled low-strength material (CLSM) onsite for bedding and embedment through the sand dunes. CLSM is made of native materials that we mixed with water and cement. It allows deeper sand to cover the pipe and provides greater side support. And because we used native materials, we didn’t need any delivery vehicles for imported embedment.
4. What time and budget challenges did your project have and what did you do to overcome them?
Time was a huge challenge because we had only a year and a half to activate this new source of water before the reservoirs dried up. We actually finished 2 weeks ahead of schedule. We also came in $25 million under budget on this project, about 20%.
Our team saved significant time and money by using a design process called WAVE, the Water Transmission Approach to Value Engineering. We analyzed the schedule and examined each possible way to save time or money, and the consequences of doing so. By asking whether each option was worth the savings, we maintained quality while staying on time and under budget. You can see that quality in our low rate of change orders. This project had fewer than 1% change orders, while the benchmark for projects like this is 6%.
Here are some of the biggest ways we saved money: For 27 miles of the pipeline, we modified the design to increase its diameter from 42 inches to 48 inches. This meant we no longer needed to construct a second booster pump station, which saved $6 million and allows a higher ultimate pipeline capacity. We used native materials for bedding and backfill for most of the pipeline, which expedited construction and saved $3 million. We had the joints on the steel and bar-wrapped concrete cylinder pipe welded from the inside after the trench was filled in. That sped up the schedule because we could keep laying pipe without waiting for welding, and it saved $1.1 million.
5. Sustainability is one the 3 strategic initiatives here at ASCE. Describe how your project adheres to being sustainable.
Sustainability was a primary driver of this project. With the surface water supplies drying up, West Texas wouldn’t have been able to sustain its growth without a reliable new supply. It’s important to note that CRMWD also worked to reduce demand through conservation. They implemented water rationing and limited outdoor watering, and they developed a water reuse plant. [The Raw Water Production Facility in Big Spring, Texas, is considered the first direct potable reuse water treatment plant in the U.S.] Another consultant on our team, Daniel B. Stephens & Associates, used groundwater modeling and simulations to determine that the wells’ impact on the aquifer would be acceptable.