Consultants tell Louisburg council town water yield is ~900,000 gpd; off‑stream reservoir proposed

Mister Palmer, a water resources engineer with Hazen and Sawyer, told the Louisburg Town Council on Tuesday that the firm’s model shows the town’s reliable water supply yield from the Tar River is about 900,000 gallons per day and described a conceptual upstream off‑stream reservoir to help meet projected long‑range needs.

Why it matters: Louisburg’s local water supply plan projects growth and potential industrial demand that could raise average day needs to about 2,600,000 gallons per day by 2070. Council members pressed staff and the consultant on near‑term vulnerabilities, permitting timelines and costs; the council did not take formal action on a project at the meeting.

Palmer said the town’s current treatment plant is sized for about 2,000,000 gallons per day and the town’s withdrawal permit (a 1996 state record cited in the presentation) allows up to 3,000,000 gpd but requires reduced withdrawals to 2,000,000 gpd during very low river flows. “Our model says the town’s supply yield is 900,000 gallons per day,” Palmer said, adding that the town currently operates close to that level and could struggle under a repeat of historic drought conditions.

Hazen and Sawyer’s study focused on an off‑stream storage option—an upstream reservoir that would be filled when river flows are high and released when flows are low. Palmer said a reservoir sized in the firm’s planning run would need about 450 acre‑feet (roughly 150 million gallons) to meet the modeled 2070 average daily demand, and that a conceptual cost range for developing such a supply is roughly $40 million to $75 million.

Palmer identified several factors that drive cost and uncertainty: the site’s soil suitability (which affects whether import or on‑site soils can form the reservoir berm), the potential need for a liner to prevent seepage, and the appropriate amount of “dead storage” (the study used a conservative 20 percent allowance). He also described permitting tasks and preliminary study costs: environmental and dam‑safety reviews and related studies were estimated at about $250,000, with preliminary engineering possibly adding a similar amount, and the firm’s review indicating the state watershed designation process could take about three years.

Council members and staff asked follow‑up questions about sediment behind the town’s low‑head dam at the intake, treated‑water storage the town already maintains, and whether treated wastewater reuse or buying finished water from neighboring systems had been considered. Palmer said groundwater is unlikely to be feasible for a system of Louisburg’s size in the Piedmont because yields are typically low (he cited typical well yields of 20–40 gallons per minute on the state website). He noted that the Army Corps and others historically recommended against on‑stream dams on the Tar River and said off‑stream reservoirs have become more common because they are easier to permit and have smaller environmental footprints than impounding the main stem.

On reuse and purchases, Palmer said treated wastewater can be a high‑quality source in some regions but that North Carolina has not yet developed the full regulatory framework for direct potable reuse; additional treatment and regulatory changes would be required. He also said purchasing finished water or building long pipelines from more distant sources (Raleigh, Rocky Mount, Henderson, Lake Gaston) is expensive and was reassessed in the county master plan the consultant reviewed.

Palmer recommended several short‑term actions for the council and staff: revise the town’s Water Shortage Response Plan triggers (the WSRP is a state filing), explore emergency purchase agreements with nearby providers or the county for temporary wheeling of water in an emergency, and conduct limited follow‑up studies (refine hydrology with USGS data, consider targeted bathymetry of storage behind the low‑head dam). For longer‑term planning, he recommended meeting with the state Division of Water Resources and completing a preliminary engineering report before committing to design or construction.

Council members praised the report’s conservative assumptions and asked Hazen and Sawyer to continue with the narrower technical work if the council directs staff to proceed. No formal motion to pursue the reservoir or to initiate the next‑phase studies was made during the meeting; the presentation was received and council members raised questions for staff to follow up on.

Votes at a glance: the meeting recorded procedural votes to adopt the meeting agenda and to adjourn; no votes were taken on water‑supply investments or project authorizations at this session.

What’s next: Palmer said the conceptual schedule from initial studies through permitting and construction could span multiple years—roughly 7–8 years to completion if the council chose to move forward—and that the town would need to refine the reservoir size and cost range in a preliminary engineering phase before seeking funding or permits.