Rainleader disconnections for commercial or multi-unit residential buildings

Information including inspection, permits, cost estimates, disconnecting your downspout, and and typical disconnection materials.

Usual sources of prohibited discharges

  • Roof drains
  • Area drains
  • Standpipes
  • Driveway & dock drains
  • Parking ramp drainage
  • Foundation drains

Commercial rainleader disconnection permit required

Although there is no fee, a permit is required before disconnection work can begin. The application is below. If disconnection work is not completed within the permit timeline, or if the application is not received by the due date, the Rainleader Disconnect Program may issue administrative citations and fines.

Rainleader Disconnection-Commercial Permit

 

Inspection required

The disconnection must be approved by the Rainleader Disconnect Program. Be sure to schedule an inspection with the Rainleader Disconnect Program after disconnection work is completed, but before it is concealed.

Primary ways to divert rainwater

See illustrations of common commercial connection methods

There are two primary ways to divert rainwater out of the sanitary sewer:

  • Reroute rainleaders through the building wall to discharge onto grade
  • Reroute rainleaders to connect to a storm drain in the street

Some buildings have flat pitched roofs where rain or snowmelt flows to one end and drains through a downspout or a drainage scupper. The downspout can discharge to the ground or connect to the sanitary sewer through a standpipe. If the downspout is connected to a standpipe, the downspout can be redirected to discharge to the ground, with the standpipe plugged or capped. Water from roofs is not allowed to flow on to a public sidewalk.

Cost estimates

Below are estimated costs for disconnection of typical roof drains for multi-unit residential and commercial buildings.

These estimates do not include permit costs. Multi-unit and commercial buildings may require additional permits depending on the work required.

Disconnection of typical roof drain in multi-unit building

4" Piping

Includes Material & Installation

Cost

30' of 4" cast iron pipe

Includes cast iron piping, drilling a hole through wood or masonry walls, labor and material costs.

$1,780

Core-drilling a hole through solid concrete or block (if necessary)

$942

Optional bronze downspout nozzle with galvanized nipple

$355

Optional concrete splashblock

$70

Total cast-iron cost (approximate)

$3,147

Piped using 4" PVC

Less 30% for time & material = $2,203

6" Piping

Includes Material & Installation

Cost

30' of 6" cast iron pipe

Includes cast iron piping, drilling a hole through wood or masonry walls, labor and material costs.

$2,508

Core-drilling a hole through solid concrete or block (if necessary)

$1,062

Optional bronze downspout nozzle with galvanized nipple

$686

Optional concrete splashblock

$80

Total cast-iron cost (approximate)

$4,336

Piped using 6" PVC

Less 30% for time and materials = $3,035


Commercial disconnection from building to storm drain in street

Contact an outside sewer and water contractor to evaluate the site and design a plan for disconnecting from the sanitary sewer and connecting to the storm drain in the street.

Installation charge will vary depending on work site conditions: depth of excavation, utilities present, storm drain access, storm drain main location in relation to building, traffic concerns, soil conditions, etc.

Above ground discharge, disconnection inside commercial building

Material

Cost

3" cast iron piping

$45.84/ft

4" cast iron piping

$53.64/ft

6"  cast iron piping

$75.90/ft

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Contact us

Surface Water & Sewers

Public Works

Phone

612-673-5625

Address

Public Service Center
250 South 4th St, Room 300
Minneapolis, MN 55415

Office hours

Monday – Friday
7 a.m. – 3:30 p.m.

Our office is closed to the public at this time