Downspouts and the sanitary sewer
Summary: In Indianapolis, downspouts must not drain into the sanitary sewer. Citizens Energy Group says they should spill onto the ground at least 3 feet from the building, and its Correct Connect program sends repair letters when it finds clear-water connections[1].
What is the rule?
Citizens Energy Group, which runs the sanitary sewer system in Indianapolis, says downspouts “should spill the water onto the ground at least three-feet away from the building”[1]. Rainwater must not enter the sanitary sewer: Citizens operates the system under the approval of the Indiana Utility Regulatory Commission, which prohibits clear water discharges to it. Clear water means rainwater and groundwater, as opposed to wastewater from toilets, sinks and showers.
Why does it matter?
Sanitary sewers are sized for wastewater, not storm runoff. Citizens explains that improper connections “can overload the sanitary sewer system by allowing clear water to enter the system, resulting in sewage overflows into our rivers and streams, and causing basement backups”[1]. It gives a striking figure: “It can take as few as six sump pumps to fill a sewer that serves two hundred homes.” A roof downspout during a heavy storm can add more. At about 10 gallons a minute for every 1,000 square feet at an inch an hour of rain, one house roof can put hundreds of gallons into the sewer in a single storm[2].
How do I tell if my downspout is connected?
Citizens’ rule of thumb: “If the downspout disappears into the ground, it may be connected to the sanitary sewer”[1]. Not every buried downspout is, because many go to a storm sewer, a dry well or daylight elsewhere in the yard. Citizens’ Correct Connect program offers information about proper connections, corrections and dye testing, which shows where the water from a given pipe ends up. Citizens also lists the other common clear-water sources: damaged sewer laterals, uncapped or broken cleanouts, and sump pumps tied into household plumbing.
What happens if Citizens finds a connection?
Citizens says that when a clear water source on private property is found, the owner “will receive a letter from Citizens informing them of the issue and the need for immediate repair”[1]. Owners can fix the problem themselves or call Citizens with questions.
What are the fixes?
- Disconnect and splash out. Cut the downspout above ground, cap the pipe into the sewer, and add an extension or splash block to get the water at least 3 feet away, and further where the ground slopes back toward the house[1][3].
- Route to a buried line that daylights. Run PVC to a pop-up emitter or to a lower point in the yard. Celtic Rainwater Systems offers this, including systems with an exterior sump pump where the yard is flat[4].
- Send it to a rain garden or barrel. The EPA’s Soak Up the Rain program promotes redirecting downspouts to lawns, gardens and rain barrels[3][5]. See rain barrels.
- Mind the neighbors. Do not aim discharge at a neighbor’s property or across a sidewalk where it can freeze.
The DOE building science guidance goes further than Citizens’ minimum for foundation protection, recommending discharge to a sloping grade more than 5 feet from the foundation[6]. The grading article explains why.
See also
- Indianapolis stormwater fee
- Drainage services
- Location and hours
- Sump pumps and basement water
- Hiring a gutter contractor
Common questions
Can my downspout drain into the sewer in Indianapolis?
Not into the sanitary sewer. Citizens Energy Group prohibits clear water connections and says downspouts should discharge on the ground at least 3 feet from the building.
How far should a downspout extend from the house?
Citizens says at least 3 feet. DOE building science guidance recommends more than 5 feet onto a sloping grade.
Where can sump pumps discharge?
Citizens says out of the house into a yard or to a storm sewer, not into the pipe that serves toilets, showers and sinks.
References
- ^ a b c d e f Our Wastewater Correct Connect Initiative. Citizens Energy Group. Accessed 9 November 2026.
- ^ Rain and Precipitation (How much water falls during a storm?). U.S. Geological Survey Water Science School. Accessed 9 November 2026.
- ^ a b Soak Up the Rain: Disconnect / Redirect Downspouts. U.S. Environmental Protection Agency. Accessed 9 November 2026.
- ^ Drainage (PVC downspout drainlines, French drains, basement drainage and sump pumps). Celtic Rainwater Systems (celticrainwater.com). Accessed 9 November 2026.
- ^ Soak Up the Rain: Rain Barrels. U.S. Environmental Protection Agency. Accessed 9 November 2026.
- ^ Foundation Drain, Gutters and Downspouts. U.S. Department of Energy, Building Science Education Solution Center. Accessed 9 November 2026.