Private Property Guidance
Before attempting to address the problem, it’s wise to uncover the source of the problem that may influence your choice of solutions. There are numerous factors that contribute to drainage problems on private properties:
- Building on land with poor drainage characteristics from low-lying elevations, wetlands, unsuitable soils, etc.
- The ground around the house is not graded properly to move water away from the foundation.
- The building foundation is located below the roadway elevation leading to rainwater channelizing around the house.
- Excessive impervious coverage including paved driveways, walkways, patios, etc.. Hardscapes increase the generation of runoff and reduce the ability for the soil to absorb water.
- Vegetation Removal can reduce evapotranspiration, or plant uptake, reducing the natural environment's ability to drawdown groundwater.
- Surrounding development can impact drainage on adjoining lots. The addition of impervious surfaces, importation of fill material, vegetation removal and alteration of land elevation can have a negative net effect on adjoining properties.
- Install a roof gutter system- Rainfall runoff from roof surfaces can account for up to two-thirds of the total runoff generated from a residential lot. Without a roof gutter system, roof runoff can lead to substantial water accumulation around the building foundation. The installation of roof gutters can aid in collecting and directing runoff away from the house.
- Install an underground downspout extension pipe- For homes with roof gutters, underground pipe extensions can be added to existing downspouts to direct water away from the home. Water can be directed to an on-site depression or stormwater control measure.
- Site Grading- In specific situations, it may be appropriate to re-grade on-site material or import fill material to shed water away from the building foundation to an on-site natural storage area or structural control measure.
- Replace impervious surfaces with pervious surface materials- Reducing impervious, or hard surfaces, and replacing with pervious surfaces can aid in reducing runoff and increase the area for infiltration. Pervious pavements are an approved low-impact development technique.
- Install stormwater control measures- The addition of on-site stormwater management control measures, in conjunction with other improvement methods, can provide additional storage and treatment of stormwater runoff. A variety of low-impact development techniques can be employed such as rain gardens, french drains, dry wells, vegetated swale, etc. to provide economically and aesthetically pleasing drainage solutions.
- At grade slab adjustments- For applications with at grade concrete slabs that experience shallow flooding depths, and in limited instances, can be modified with an additional layer of concrete installed on top of the existing slab. Prior to considering, consult with a Nags Head building inspector to determine if adequate vertical clearances exist.
- Plant Vegetation- The planting of vegetation can aid in the uptake of groundwater.
Prior to proceeding with any of these recommendations, please consult with the Town first to determine the level of permitting required. For additional assistance, contact Kate Jones, firstname.lastname@example.org. at 252-449-4209.