Pounding droplets of rain land and splash on the blue tarp covering the woodpile outside the window. The drops glide down the slippery material, pooling near the ground where the tarp is bunched up and restrained by a piece of old lumber from the pull of the whipping wind.

Soon the pool outruns its bounds, spilling over into a depression in the grass. The water builds and builds, causing a little stream to form, running down the driveway in a curvy, bubbling watercourse, over stones and gravel to the roadside ditch. There, it meets gushing gallons of water coming from other directions and joins in the flow to lower ground.

In autumn, as in spring, our attention may be drawn to the flow of water created by rain. It may come to rest on pools in the landscape – to the nature of how water works, flows and influences the growth of plants in our yard and the utility of our landscape areas. Carefully managed, the diversion of water through the landscape can create a pleasant, functional, harmonic living environment. Neglected, water can be among the most destructive elements.

In Maine, land is seldom flat; we are blessed with variable terrain that rapidly sheds water and adds visual interest to the landscape in the form of tree-covered rolling hills and arching mountains for which our state is known. In our yards, sloping landforms play an integral role in the runoff of water. If drainage problems exist in our yard, we can look to nature to learn a bit about creating effective drainage. We can use that knowledge to reduce or eliminate nuisance seasonal or season-long pools and puddles.

The basic principle of drainage is a simple one: Water runs downhill. In nature, water runs off the steep slopes of mountainsides and naturally makes its way to the low-lying depressions of streams, rivers or lakes. In some areas, particularly in critical areas near the ocean, marshes filter the water. Marsh grasses capture soil particles, “cleaning” surface water before it enters the vast sea.

In the process of landscape design, we manipulate landforms to achieve the effects found in nature. We pile soil in mounds to form berms – miniature man-made mountains – to create an increase in grade. We dig ditches with a gently sloping and carefully calculated grade to divert water away from the home and other functional areas in the landscape.

In nature and in our yards, the greater the grade or slope of the landform, the faster the rate of drainage. Generally speaking, the greater the pace of runoff, the greater the risk of soil erosion by running water. Drainage ditches become more effective – that is, they may reduce the incidence of erosion – if they are crafted in such a way that uses the minimum slope necessary to drain the site, spreading the drainage over a wide base.

In practical terms, this means a winding drainage pattern that crisscrosses the grade (rather than one that runs directly up and down it) is most effective. Also, the planting of vegetation in the base and along the sides of a drainage ditch mimics the natural effect of a marsh and should be a major emphasis of maintaining drainage systems around the home.

Thoughtful attention to what’s happening with the water in our yards is a worthwhile measure in autumn. Not only can poor drainage affect the lowliest members of the turf grass family and the mightiest oaks, but poorly managed drainage systems – those that are not thoughtfully planned, properly executed and carefully maintained – can cause a major disturbance in natural drainage of undisturbed landforms, and may affect water quality over time.

Diana George Chapin is the NEWS garden columnist. Send horticulture questions to Gardening Questions, 512 North Ridge Road, Montville 0494,1 or e-mail dianagc@midcoast.com. Selected questions will be answered in future columns. Include name, address and telephone number.