CelticRainwater.wikiA sourced reference on Celtic Rainwater Systems and rainwater control for Indianapolis homes

Glossary

CelticRainwater.wiki: a sourced reference on Celtic Rainwater Systems, gutters and drainage in Indianapolis

Prepared by the Celtic Rainwater Wiki editorial team · Created · Last checked

Summary: Definitions of 29 terms used on this site, from base billing unit to swale, with sources where a term has a local or legal meaning[1][2].

Read this first: CelticRainwater.wiki is an independent reference built from public records, government publications and the company’s own website. It is not run by Celtic Rainwater Systems, and statements the company makes about its own work are attributed to it. Services, hours and contact details can change, so confirm them with the company at (317) 450-4648. Drainage and plumbing questions on a specific property belong with a qualified professional and, where relevant, Citizens Energy Group or the City of Indianapolis. How pages are checked: editorial policy.

Index

B · C · D · F · G · H · I · K · L · M · P · S

B

Base billing unit (BBU)
The unit for the Indianapolis stormwater fee: up to 1,000 square feet of impervious area, billed at $1.65 a month in 2026[1].

C

Clear water
Rainwater and groundwater, as opposed to wastewater. Citizens Energy Group prohibits clear water in the sanitary sewer[2].
Cleanout
An access pipe, usually 4-inch plastic with a cap, for inspecting or clearing a sewer lateral or drain line[2].
Correct Connect
Citizens Energy Group’s program to find and remove clear water connections to the sanitary sewer[2].

D

Downspout
The vertical pipe that carries water from the gutter to the ground or a drain line.
Drainline
A buried pipe that carries downspout water away from the house; the company recommends PVC[3].

F

Fascia
The board along the roof edge that gutters hang from[4].
French drain
A fabric-lined trench of washed stone around a perforated pipe that collects and carries away water[5][3].

G

Galvanic corrosion
Corrosion when two different metals, such as copper and aluminum, touch in the presence of water.
Geotextile fabric
A permeable fabric that lets water through but keeps soil out of drain stone[3].
Grade
The slope of the ground. The IRC requires a 6-inch fall in the first 10 feet from a new foundation[6].
Gutter guard
A cover or insert that keeps debris out of a gutter while letting water in[7].

H

Half-round gutter
A gutter with a semicircular cross-section, often in copper[4].
Hanger
A bracket that holds a gutter to the fascia.

I

Ice dam
A ridge of ice at the roof edge that traps meltwater behind it[8].
Impervious area
Hard surface that water cannot soak into, such as roofs, driveways and patios; the basis of the stormwater fee[1].

K

K-style gutter
The common gutter profile with a flat back and a molded front.

L

Leader head
A box at the top of a downspout that collects water from a gutter or roof outlet[4].

M

Micromesh
A fine stainless steel mesh guard that stops small debris such as needles and seeds[7].

P

Perimeter drain
A drain around the base of a foundation, inside or outside, that collects groundwater.
Pop-up emitter
A cap at the end of a buried drain line that opens to release water onto the lawn[3].

S

Sanitary sewer
The sewer that carries wastewater from toilets, sinks and showers to a treatment plant[2].
Scupper box
A box that takes water through an opening in a parapet wall or flat-roof edge into a downspout[4].
Seamless gutter
A gutter formed on site from a coil to the length of each wall, with joints only at corners.
Sewer lateral
The pipe connecting a building’s plumbing to the public sewer[2].
Snow bar
A bar fixed above the eaves to hold snow in place so it does not slide off in a mass[4].
Soffit
The underside of the roof overhang, often vented[4].
Sump pump
A pump in a basement pit that lifts collected groundwater outside[9].
Swale
A shallow, broad channel in the ground that carries surface water away.

See also

Common questions

What is the difference between a leader head and a scupper?

A leader head collects water at the top of a downspout; a scupper box takes water through an opening in a wall or flat-roof edge.

What is clear water?

Rainwater and groundwater, which must stay out of the sanitary sewer in Indianapolis.

References

  1. ^ a b c Stormwater User Rate, Payment Options and Credit Manual. City of Indianapolis (indy.gov). Accessed 9 November 2026.
  2. ^ a b c d e f Our Wastewater Correct Connect Initiative. Citizens Energy Group. Accessed 9 November 2026.
  3. ^ a b c d Drainage (PVC downspout drainlines, French drains, basement drainage and sump pumps). Celtic Rainwater Systems (celticrainwater.com). Accessed 9 November 2026.
  4. ^ a b c d e f Gutter Installation. Celtic Rainwater Systems (celticrainwater.com). Accessed 9 November 2026.
  5. ^ French drain. Wikipedia. Accessed 9 November 2026.
  6. ^ 2021 International Residential Code, Section R401.3 Drainage. International Code Council. Accessed 9 November 2026.
  7. ^ a b Gutter Guards. Celtic Rainwater Systems (celticrainwater.com). Accessed 9 November 2026.
  8. ^ Attic Air Sealing, Insulating, and Ventilating for Ice Dam Prevention. Building America Solution Center (PNNL, U.S. DOE). Accessed 9 November 2026.
  9. ^ Sump pump. Wikipedia. Accessed 9 November 2026.