Forested Watersheds Raise Drinking Water Quality and Lower Infrastructure Costs

By Chloe Brantley 

The area downstream of Rio Verde Springs, the source water for Green River Valley Water District.
Photo by Kirsten Delamarter

Protecting watersheds is one of the most important ways to ensure reliable, safe drinking water.

In 2015, the Green River Valley Water District (District) learned of a timber harvesting operation in the Rio Verde Springs watershed in Hart County – the main water source for the District serving nearly 17,000 Kentuckians in five counties.  The District implemented a source water protection plan — prepared by the Kentucky Rural Water Association (KRWA) and approved by the Division of Water (DOW) — and by 2018 had acquired the 141-acre parcel.

While only a small fraction of water suppliers have direct control over their watersheds, the District has protected 224 acres within the Rio Verde Springs basin.

“I think water is the most precious commodity we have,” said David Paige, manager of the Green River Valley Water District. “The quality of the water we produce depends on the land that surrounds it. It is our duty to protect the Rio Spring and produce the best drinking water possible for our customers today and for generations to come.”

Rio Verde Springs is the primary source water for the district that it treats and distributes to wholesale customers in Hart, Green, LaRue, Barren and Metcalfe counties. It lies along a bend on the north side of the Green River and consists of five identified perennial springs whose flow is impounded by a dam to form a small reservoir.

The district’s Source Water Protection Plan was prepared by the Kentucky Rural Water Association (KRWA) and approved by the DOW. Matt Glass, source water specialist with Kentucky Rural Water Association said his organization provides technical assistance with the development of source water Protection plans to rural communities throughout the state.

“These plans act as a water utility’s primary defense against potential contaminants and effectively safeguard drinking water sources by maintaining water quality at the source,” Glass said. “The proactive approach that the Green River Valley Water District took by acquiring the land within their source water protection area … has not just maintained water quality, but potentially improved it.” 

Water falls near a spring owned by the Green River Valley Water District in Hart County.
Photo by Kirsten Delamarter

Rio Verde Springs and Source Water Protection

The “Rio Verde” valley, created by the Green River, was described by early European explorers in the mid-1700s as “the most magnificent broadleaf forest in the world.” The Green River in this stretch is one of the most biologically diverse rivers in the world and contains extremely rare species, including mussels and fish.

Fed by numerous springs that bring clean, cold water to this stretch of the river, it takes on what some have described as a bluish green color more reminiscent of the shallows of the Caribbean than southcentral Kentucky. The karst topography surrounding the Green River in Hart County produces some of the highest water quality in Kentucky, but it is also what makes Rio Verde Springs highly susceptibility to potential contamination.

Healthy watersheds are widely viewed as an essential and cost-effective component of providing safe drinking water. This critical natural infrastructure delivers benefits such as filtering pollutants, sediment, and harmful bacteria. It controls base flow and water temperature, reduces erosion and mitigates flooding. Protecting and restoring the natural infrastructure of source watersheds can directly enhance water quality and quantity.

Source water protection – including protection of groundwater, wellheads, aquifers and watersheds, has emerged as a framework for protecting the services that healthy watersheds provide. It is widely viewed as an essential and cost-effective component of a multi-barrier approach to providing safe drinking water. However, it is primarily a voluntary activity that may include planning and activities such as forest protection, reforestation, and improvement of agricultural practices on lands near water sources.

Evidence of logging activity can be seen in the source water protection area of Rio Verde Springs. The Green River Valley Water District purchased this 141-acre parcel to protect the springs. Photos by Kirsten Delamarter.

With growing interest in source water protection as a means for mitigating public health risks and avoiding expenditures at drinking water treatment plants, it is increasingly important to understand the costs and potential benefits of better watershed management.

Forested Watersheds and Public Drinking Water Supplies

These benefits can be seen in higher-quality drinking water within forested watersheds, when compared with increased water treatments costs for source water originating from other types of land use.  As seen in this graph, protecting and managing forests in source watersheds provides a cost-effective
alternative or complement to maintaining, updating, or replacing expensive water treatment infrastructure.

% of Watershed ForestedTreatment and Chemical Costs (per million gallons)% Change in CostsAverage Treatment Cost (per day at 22 million gallons)
Table 1. Water treatment and chemical cost based on percent of forested watershed (From Ernst et al. 2004)

A study of water suppliers estimated a 10% increase in forested watershed resulted in a 20% decrease in treatment costs. Another study found that decreased forest cover was related to decreased water quality, while low water quality was related to higher treatment cost (Freeman et al., 2008). The results of many these studies suggest the value of maintaining healthy forested watersheds when considering the treatment alternatives.

Rio Verde Springs.
Photos courtesy of James Nunn, Green River Valley Water District Water Treatment Plant superintendent.

Source Water Protection Resources

In many respects, the 1996 amendments to the Safe Drinking Water Act marked a return to time-tested principles and reflected a renewed national focus on source water protection as a tool to prevent the contamination of drinking water supplies. There are many tools and resources to leverage local, state, and federal resources to develop source water protection strategies. Public and private assistance and funding programs are available to help partners implement voluntary protection efforts.

Many communities are finding innovative ways to leverage funding sources through the creative application of traditional tools, such as the Clean Water State Revolving Fund and new programs. There are numerous state and federal programs that support source water protection, such as the  US Environmental Protection Agency’s (EPA) Clean Water Act, Safe Drinking Water Act, and Source Water Protection program; and the Kentucky Division of Water’s Source Water Protection Program.

Green River Valley Water District Water Treatment Staff, James Nunn and Emily Hoffman, and Kentucky Rural Water Association, Source Water Specialist, Matt Glass standing in front of the dam at Rio Verde Springs that is the source water for customers in Hart, Green, LaRue, Barren, and Metcalfe counties.
Photo by Kirsten Delamarter

Through the DOW’s  Source Water Protection Story Map and Source Water Protection Viewer one can see protection resources available and see source water protection areas, data, information and plans for each public water system in Kentucky.

The Division of Water would like to recognize the significant and important efforts the Green River Valley Water District has taken to protect their source watershed from potential contamination and to ensure the delivery of safe drinking water. Please visit their website at For any source water protection assistance, please contact Chloe Brantley with Kentucky Division of Water at or 502-782-6898 or Matt Glass with Kentucky Rural Water Association at or (270) 843-2291.

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