Harrisburg's Drinking Water Starts In The Clouds

Evaporated water condenses into clouds and falls back to the ground as precipitation, like rain or snow. When precipitation hits the ground it collects as streams along the way. The land area where water flows into a stream is called a watershed. For Harrisburg's water, rain collects in a 22 square mile watershed in Clarks Valley that drains into Clarks Creek.

DeHart Dam: The Strength of Harrisburg's Water Supply

DeHart Dam was built in 1940 along Clarks Creek 20 miles northeast of Harrisburg to create a reliable and pristine source for drinking water. The DeHart Dam is over 120 feet high and creates a reservoir that can hold up to 6 BILLION gallons!

From DeHart to the City and the Water Services Center

Water from the reservoir flows downhill through a 42" diameter pipe over 20 miles to the Water Services Center for treatment. This fast-flowing water from the dam is used to turn a turbine and generate electricity!

This pristine source water is then sent to clarifiers, which is like letting a murky glass of water settle until the sediment all falls to the bottom, just on a huge scale! The clarified water then undergoes filtration before disinfection to meet the highest standards for drinking water.

Next Stop: Reservoir Park

Water is pumped from the Water Services Center to three reservoirs that can hold almost 49 million gallons of water. The reservoirs are positioned at an elevated point in Harrisburg to give you great water pressure.

A Network of Underground Pipes – Water Distribution

Ranging in size from 4" to 42" in diameter, there are almost 200 miles of pipe that run under your streets. This complex system delivers water to homes, businesses, schools, and almost 1,800 fire hydrants. This water is always on and ready to meet your needs.


Some rain collects naturally into streams, creeks, and rivers. Some of it is used by green vegetation, but when rain falls on rooftops, sidewalks, or other hard surfaces it becomes stormwater and goes on a wild ride down your street and into the stormwater or combined sewer system.

Stormwater System – More Underground Pipes!

There are almost 4,000 storm drains that collect stormwater in Harrisburg. While most of the system is a combined sewer system, about 20% of the system collects stormwater separately from wastewater. This stormwater is then directed into nearby streams, creeks, and rivers.

A Combined System

Most of Harrisburg’s sewers, like other cities developed during the 19th century carry both wastewater and stormwater (rain water runoff). These systems are known as Combined Sewer Systems (CSS). This combined system handles most rain events but larger storms can cause diluted sewage to overflow into Paxton Creek and the Susquehanna River called combined sewer overflows (CSOs). Capital Region Water is currently working to minimize these CSOs.


When you brush your teeth, wash your dishes, or flush the toilet, that water has to go somewhere. Though it ultimately returns to the Susquehanna River, a very important and rigorous process is in place to ensure that only clean water is being discharged.

Another Network of Underground Pipes – Sanitary Sewers

Wastewater flows through a sewer system which is like a gigantic system of drains that funnel all of Harrisburg's wastewater to the Advanced Water Treatment Facility (AWTF) to be cleaned up.

Wastewater Treatment Facility

The Advanced Wastewater Treatment Facility is the final stop for your water before it reaches the Susquehanna River. The AWTF treats water from the sewer system through a series of physical, chemical, and biological processes – little bugs help break down the waste! Water is then disinfected before releasing it to the Susquehanna River.

Valuable Byproducts: Renewable Energy and Bio-solids

One of the byproducts of breaking down waste at the AWTF is methane. This methane is collected and burned to generate electricity and heat! The remaining solids are then dried and used on farms or abandoned mines to help fertilize the land.