Securing our long-range water supply


Fellow Citizens,

Few public services are more important than having an adequate supply of good quality water. In this context, Jordan Lake has been a subject of controversy in Chapel Hill for over 50 years and it’s still going strong! I have been on the OWASA Board for five years and have spent a lot of time on our future water supply planning. I am sending along some information that I hope will contribute to the kind of factual, reasoned discussion that we need on this critical community issue.

We are planning an update of OWASA’s water supply plan for 50 years in the future, a long time with many factors that are hard to estimate. How much growth will occur? Will the increasing weather extremes produce a drought worse than we have experienced in the past? One very favorable development is the substantial reduction in water use in the OWASA system in the first decade of the 2000s, a result of conservation habits learned during two severe droughts, extensive use of recycled wastewater by the University, water rate changes that create incentives to conserve water, and the increasing water efficiency of household appliances. Our projections of future water use are now 17% lower than those made as recently as 2010. Fortunately, our current water sources, University Lake, Cane Creek, and the Quarry Reservoir will meet almost all of our needs to 2070, but toward the end of this period the margin of safety gets too thin. We need another water source to supplement these existing sources when required. In August 2020, the Board reviewed an extremely wide range of potential alternative sources. See this link for details. 

A stone quarry west of Town has been acquired by OWASA and contributes to the security of our supply. See pages 5.38 to 5.41 of the link above for a discussion of the Quarry Reservoir. Enlargement of the quarry to store more water is underway and will be completed in late 2030 when mining will stop. The larger quarry will be filled with water and will add an additional 2.1 million gallons per day (mgd) to our water supply yield by about 2035. The weakness of the quarry is that it has no streams flowing into it to replenish it. The quarry has to be filled by pumping water from Cane Creek, so it is dependent on the same watershed and can only add to our water supply resiliency to a limited degree. 

Jordan Lake is extremely drought resistant, making it a good choice for a new source of water to use in extreme droughts, when other sources might be temporarily off line, or if growth in demand exceeds our predictions. OWASA requested and received a Jordan Lake allocation from the State in 1988 to make sure that this alternative would be available when needed. OWASA is exploring how we can obtain our 5 mgd allocation of water at Jordan Lake through partnership agreements with other utilities. Durham, Chatham County, and Pittsboro are potential partners in building a new water intake on the west side of Jordan Lake. These other utilities have short-term needs for water, while OWASA has a long- term need. We are evaluating ways of meeting our long-term need as economically as possible. Since several partnership possibilities exist, there is no price tag yet determined for this OWASA alternative.

OWASA has a close community of interest and a strong working relationship with the City of Durham. Durham has supplied us water during emergencies, such as the fluorine over-feed episode a few years back. We have sold them water for a substantial period when they were upgrading a water treatment plant. This kind of regional cooperation is a key element in water supply security and resiliency. We are fortunate in the Triangle to have extensive regional cooperation in water supply planning and many interconnections, allowing utilities to help each other out when needed. Because of our adjacent location, existing interconnections, and our history of mutual support, I believe that close association with Durham is desirable and may help us meet our future needs in the most economical way. 

Jordan Lake serves currently as a water source for hundreds of thousands of Triangle residents, subject to the oversight and regulation of state and federal agencies, including frequent testing of both water in the reservoir and treated drinking water to determine whether it meets standards. Public water supplies from Jordan Lake are meeting all safe drinking water standards. A recent OWASA Board agenda included extensive comparisons of Jordan Lake and other Triangle water sources. See Attachment 3 of this link starting on page 6.43 for this data and a map on page 6.49 showing sites where water samples were taken. 

The main tributaries of Jordan Lake are the Haw River and New Hope Creek, both with some developed urban areas and associated runoff in their watersheds. Large reservoirs like Jordan reduce many pollutants through several processes, including chemical breakdown of compounds over time, sedimentation, and dilution. The unique hydrology of the Lake causes the concentration of various artificial substances to vary considerably throughout the lake as the data referred to above shows. For this reason, water samples from the Haw River vary greatly from samples taken in Jordan Lake at various points. The existing Cary water intake at Jordan and the proposed new western intake are located in the part of the reservoir with the best water quality. Cane Creek Reservoir does not have urban areas in its watershed, but is exposed to pollution from agricultural chemicals and pesticides, animal waste, and application of sewage sludge to fields. 

Whether we would prefer it or not, we live in an industrial age and are subject to manufactured chemical substances in our food, air, water and household environments. New pollutants are discovered from time to time, such as the PFAS chemicals, but our ability to detect and control new pollutants is also advancing rapidly. Jordan Lake is systematically monitored for both regulated and emerging pollutants. After reviewing comparative data, I personally find Jordan Lake to be a completely satisfactory water source and a desirable complement to our existing sources. I have confidence in the ability of our monitoring and regulatory system to keep Jordan as a safe water source. 

In my five years on the OWASA Board I have not seen other Board members or the staff motivated by anything other than providing our customers a safe and adequate water supply, which is a challenging responsibility. We understand that decisions about managing community growth, zoning and our service area boundary are made by the governing bodies of Chapel Hill, Carrboro, and Orange County, partly individually and partly collectively through the Water and Sewer Boundary Agreement. Development interests who may want to enlarge our service area take their concerns to the governments who have this authority, not to the OWASA Board. 

 The current status is that the OWASA Board and staff have selected Jordan Lake as the preferred alternative for a supplemental long-range water supply source. The means of delivering this water to us and the cost are under investigation and evaluation. The Board will approve a revised Long-Range Water Supply Plan when full evaluation of the alternatives has been completed. Concerned citizens should sign up on the OWASA website to receive periodic updates on this planning and can attend our virtual Board meetings, send us their comments and find extensive background information on our website.

John Morris 


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2 Comments on "Securing our long-range water supply"

  1. Nice article, John. It’s been a while since I’ve thought this issue through, but I was leaning towards the Jordan Lake allocation over the Durham interconnection, primarily because it’s a better safety valve on quantity in extreme drought situations. Thanks to you and the rest of the Board on very carefully considering this critical issue.

  2. Well done, John.

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