Homeowners often have questions about drainage issues between properties. Minor changes in drainage patterns such as modifying the discharge from a downspout, installing a raised planter, or planting or removing vegetation do not require a building permit.
General drainage guidelines
- Roof and surface drainage collected by a system or pipe should be discharged approximately 10 feet from the edge of the property to allow some natural spreading of the water. Concentrated flow shouldn’t be discharged at a neighbor’s property line, or onto the sidewalk, street, curb or gutter. If the slope is toward neighboring properties, drainage should be released so that it will flow away from downslope structures to the maximum practical extent. If feasible, don’t tie several downspouts together creating concentrated flow in one pipe, but allow for sheet flow through grass or mulch to absorb and divert flow.
Additional water retention strategies can be used to reduce downslope impacts, such as French drains, soil amendments, rain gardens or similar features. At no time will any roof, driveway or foundation drains be allowed to be connected to the sanitary sewer line.
- Property owners shouldn’t build systems or structures that result in standing water on a neighbor’s property. Fences and retaining walls shouldn’t concentrate runoff as to cause a negative drainage impact. All stormwater drainage systems, pipes, swales and ditches shall be maintained in a manner that causes water to drain from a higher to a lower elevation without causing a backup of water onto any lot or street.
- New sump pumps that are installed must surface release a minimum distance of at least 10 feet from the edge of the property. Sump pumps must not discharge to the sidewalk, street, stormwater planters, pervious driveways or to the gutter. Sump pump discharge must not result in concentrated flow to off-site owner’s property.
- The fill around existing structures should be properly compacted and graded to slope away from the house, with the objective of achieving at least a 5 percent slope for a minimum of 10 feet (making the ground 6 inches lower than the ground surface at the house wall). This may not always be feasible, depending on the existing grading and characteristics of the existing structure, side yards, and vegetation. As much effort should be made as feasible to ensure positive drainage away from a structure’s foundation. If necessary, a shallow swale, or drainage path, can be graded to help carry runoff away from the building foundation or from low areas in the yard where the soil has settled.
Disputes Drainage disputes between private property owners are private matters that must be handled directly between the affected property owners.
- The Township has over 8,700 catch basins
- The Township has 2 major watersheds or 6 minor watersheds.
- How much stormwater falls? Over 1,600 outfalls. We have over 170 infalls in our system
- In 2018 alone, approximately 25 billion gallons of stormwater passed through the Township’s system
- The township is 23 square miles in area.
- The Township has 12,337 parcels of land.
- The Township is 72.9% developed.
- There are 4.4 square miles of impervious surface in the Township.
- Use slide below to pull other general Cranberry Township facts.