Landscape Drainage Problems on a Slope

Erosion

• If the slope spans a large area, water runoff finds the path of least resistance and flows down the steepest part of the slope. The ground mulch along this path typically floats away, leaving eroded patches of dirt behind. Several solutions serve both utilitarian and ornamental concerns. Planting a bed of hardy shrubs surrounded by inorganic mulch, such as large gravel, helps absorb water and retain soil once root systems develop. Unlike large nuggets of mulch, gravel mulch won't float away.

Root Rot

• Water runoff puddles at the bottom of slopes when it has no place to go. Plants and other growth die of root rot when exposed to saturated soil for extended periods. Adding flood-resistant grass and trees, such as black willow or Eastern cottonwood trees, absorb significant amounts of water.

Soft Spots

• Spongy or soft patches of grass on a slope indicate that waterlogged ground. This occurs over flat patches at the bottom of the slope or in slopes where soil has a high clay consistency. Installing perforated drainpipes through problem areas carrying away excess water to a ditch or street gutter solves the problem. Instead of covering the pipes with clay soil, add a layer of gravel to block debris, and then mix the soil with an equal portion of sand or compost. This aerates the soil making it more absorbent and allowing water to pass through.

Dry Top

• Soil at the top of a slope is often dry and exposed to full sun. Planting full-sun, drought-resistant shrubs and groundcover, such as juniper and butterfly bush, adds color and texture to the slope's crown. Surrounding the plants with compactable mulch, such as shredded wood chips or large pebbles, retains moisture and insulates growth.