Botanica Atlanta Landscape Design

Atlanta recently got over 25 inches of rain and many residents experienced the ravages of our floodwaters in some way or another. High volume preciptation created problems with both pooling water and fast moving water, both problems that can be managed in the landscape.

Site grading is the most elemental of drainage strategies homeowners can use to control the flow of water across their properties from areas of undesirable over-saturation to collection areas for later use or to municipal stormwater systems. Generally houses should be sited so that stormwater drains away from the house.

If downspouts create pooling or erode the soil, or if high volumes of water enter from a neighboring property, dry creek beds can be used to direct rainwater off the property or to a collection area such as a dry pond, retention pond or rainwater harvesting cistern. Dry creek beds can be designed and specified to compliment the aethetics of your landscape and add a new dimension to your site vistas.

Photo Credit: Sturgis Rock Solid Solutions

French drains are appropriate for controlling excessive moisture around foundations, where hardscapes and softscapes create pooling and where grade depressions create ponding in undesirable locations. French drains are basically just trenches filled with gravel. Sometimes drainage pipe is installed. French drains act as disguised dry creek beds, and can transport water under turf or other landscape features.

Including native wetland plants in high moisture areas can also control water excesses on site. Winterberry hollies, inkberry, florida anise, willows, red dogwoods, birches, cedars, horsetail, ornamental grasses, lillies, and rose mallow are all species native to Georgia which can withstand or even thrive in excessive moisture.

If the recent rains pointed out site drainage issues on your property, talk to a qualified landscape designer for advice about how to manage drainage, even harness excessive water on your property for asethetic or functional gain.

Although the recent rains have alleviated the severe drought of 2007/8, the Atlanta area will still get dry months, and planning for a dry summer should start now. 

In recent years, because of the drought, a number of innovations in water saving systems have taken place.  The most common one is a simple rain barrel.  These have come a long way from the old fashioned wooden barrel that collected water on rural properties.  Fiskars have come onto the market with very acceptable designs that are easy to install and are available at larger hardware stores.

The barrels come complete with hardware, so that all you need to do is assemble and install.  Locate the collection system near a downspout, and on a level spot.  The assembly does require that you saw into the downspout at two different places so that the diverter hose can be inserted.  The hose carries water coming down the spout and into the barrel.  When the barrel is full, the hose becomes inactive and water continues down the spout to the ground drainage system.

The biggest drawback with the system as it stands right now is that the only outlet is a spigot.  This is fine for a watering can to refresh hanging baskets, but not so great for larger areas which need a soaker hose or other method of water delivery.  Putting a tap with a hose attachment onto the barrel is not difficult, but you will have to purchase the parts such as an outlet tap, connector, washers etc.

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A Fiskars Water Collection System modified with a hose outlet as well as the spigot fixture.

By the middle of this season, a new version of the Fiskars rain collection system will be on the market, which includes a modified tap that has the threading to attach a hose.

For larger, more complex water collection systems you can use cisterns and underground tanks. For more about these systems visit www.atlantarainharvest.com .

Drainage patterns in your garden can negatively effect the optimal use of water. 

Most modern homes have a system that is geared to carrying water away from the whole area, reducing ponding and preventing dampness around basement areas. That is a fine model for flood prone areas and areas that do not suffer from regular droughts, but not so good for Atlanta which is facing a second year of watering restrictions. Learning how to change the drainage patterns can ensure that more water stays on your lot, and less is diverted to the storm sewers.

The drainage on your property can be adjusted such that it can help conserve the water that we do get, and in many cases this water, particularly from spring and summer storms, can be stored for later, drier periods. Knowing how to capture the water and effectively distribute it may need a professional, but there are some things that a homeowner can do to adjust the flow patterns such that they are more beneficial to the landscape as a whole.

Identifying Low Points

When heavy rains occur, even if they only last a few minutes, it becomes obvious where your low points are.  Look for standing water just after the storm.  You can also see grass lying down in the direction of flow when fast moving water passes over it.  This will indicate the direction of drainage.

Generally you will find the low spot and drainage areas are at the corner of the property, or a group of properties.  Placing a collection system at this point will stop the water leaving your property.  Underground cisterns are a convenient way to store this excess water. With a pump installed, the stored water can be distributed as needed.

Altering the Flow Pattern

Water that leaves the property by running along the back lot line can be retained on the property if the flow pattern is adjusted.  Just as ancient irrigation systems were made to channel water in a specific direction, modern landscape design can also be designed to retain water and drain it to a designated place. 

Altering the overall flow of the lot, by creating swales and hills, will divert the storm water effectively, but it is wise to get professional advice prior to major reworking.  Draining too much storm water towards your home can cause major structural problems.

Small scale trenches and channels through a vegetable bed are quite within the scope of a homeowner. Instead of using boards to retain soil in a raised bed, trench around the bed and heap the soil to the middle, thus giving a channel around the edge of the area to retain, and distribute, storm water when it occurs.

Knowing how to change the drainage pattern will make the best use of rainwater and help ensure that your garden gets the maximum amount of water available.

Perennial beds are best watered with soaker hoses.

A tremendous amount of water is wasted when people water their gardens. Most of the wasted water either goes to run off or is evaporated. Neither of these are any use to the landscape. Picking the right sort of water method for your garden depends on what you are growing.

Overhead Sprinklers

Overhead sprinklers are the worst culprit as they fling water in every direction and on a hot day the tiny droplets evaporate before they reach the ground. However, sprinklers are probably the best method of watering newly laid turf or lawns. To maximize the water getting onto the surface, water very early in the morning when the temperatures are coolest. Cool air temperatures cannot hold as much water as hot air and the addition of sprinkler-driven water will result in much more getting onto the lawn where it is needed.

Overhead sprinklers are not the way to go with herbaceous borders. Getting the leaf surface wet can lead to mildew problems particularly in humid weather. Much less water actually reaches the surface from sprinklers and as the plant needs moisture at the root level, you will need to run the water for much longer.

Soaker Hoses

Soaker hoses are made from a sponge like material that allows water to ?leak? out. If placed carefully and covered with mulch, these will irrigate the surrounding 3 ? 6 inches. This type of hose is great for irrigating a large perennial bed where you want to get water to the roots of many items in the same general area.

Drip Irrigation

This method of watering is great for things that are spread apart. A shrub bed would be the ideal situation where individual shrubs are several feet apart. Each shrub needs water but the area between the shrubs does not. Drip irrigation carries water along a pipe and diverts it to a few discrete areas. One t-junction will send water to each shrub. This makes watering more targeted and thus more useful for the specific landscape.

Whichever sort of landscape you have, you can mix and match the irrigation to suit the area that you need to irrigate.

For more ideas on efficient irrigation visit: http://atlantawaterharvest.com.

Rain barrels are probably the most common way capture water from a storm to use in the landscape. There are many situations though where a homeowner wants to save water, but they also want discrete collection containers.

The main source of collectible water is from downspouts.  Rain that falls onto the roof follows down the slope of the roof line and is diverted into the gutters, then into the downspout. From there the water is taken away from the foundation and usually drained into storm sewers. Older homes could find that the water is diverted to a low spot on the property which floods when you get heavy storms.

This water is the prime source of collectible landscape water. 

When designing a rainwater capture system for your landscape there are a few considerations, the prime one being ? where do you want to water?  If your favorite perennial border is 75 feet from the collection point, you will need hoses or even buckets to get it from the point of collection to the point of use. This is the major drawback with rain barrels. A rain barrel is collecting at the base of the downspout, which is next to the house.  For foundation plantings and things close by this is an adequate source of supplemental water.  However, for plants on the far side of a pool, you would have to string ugly hoses around the pool to water the landscape, and that is not quite so convenient.

This is where alternative collection sites need to be sited.  Funneling the water from the house to a distant collection point needs to be designed carefully.  Water can easily be backed up and cause your basement to fail.  Remembering that water needs to flow downhill is critical, and for most landscapes this requires the collection tank to be sited below ground.  Capacity of the tanks will vary but even fountains can be sustained by larger tanks. 

Once you have the collection side of the operation organized, then you can deal with the delivery.  Unless your garden is down hill from the tank, you need to use a pump to get the water to where you want it. A simple sump pump mechanism will work to evacuate the water from the cistern, but a stronger pump is required if you want sufficient pressure to carry the water along soaker hoses and around the garden.  A tap that has a hose nozzle fixture is the most convenient and this requires an electrical line for power.  Simply activate the pump to get the water flowing through your hoses.

Overall water collection for use in the landscape is not only needed on those hot dry summer days, but with the environmental and climate concerns being important too, having someway to sustain a landscape without using public water is imperative.

For more information on storing water in cisterns check: http://atlantawaterharvest.com/