Dire Straits

Poor drainage rarely wears a disguise. Most homeowners notice symptoms of soppy foundations in their wet basements or diagnose their own mushy, marshy back yards. Soaked plants get sick, soggy turf thins and dies out, and smelly soil indicates rotting.

Retaining walls offer one solution for properties with drainage difficulties.

If anything, muddy shoes tell the truth and, chances are, the neighbors won’t hesitate to offer their own assessment when they find their driveways serving as catch basins for excess runoff. These signs can leave homeowners knee-deep in drainage dilemmas. But that doesn’t mean their landscape plans are sunk, or that their grounds are destined to remain waterlogged. Fact is, contractors need to consider drainage on all properties before installing or designing plans, pointed out Bill Eiserman, production manager, Mariani Landscape, Lake Bluff, Ill. “You have to deal with [drainage] on every site, and if you don’t, you will end up with a long-term problem,” he warned. “It might not show up right away, but eventually it will.”

ASSESS THE MESS. Drainage issues aren’t contained within property lines, so contractors need to “think big” when assessing sites and offer solutions that aren’t short-sighted. “There are two different systems,” Eiserman identified. “There is a global system and a site system. You have to drain each differently, and if the whole subdivision drains into one lot and you’re working on that one lot, it will be difficult to keep that area dry.”

Problematic, perhaps, but not impossible. The lay of the land is the first clue: Does the property slope toward or away from the home? Are downspouts directed away from the home’s foundation? Does the back yard slope into a ravine? How does the property’s grade compare to others nearby? Where is the water running? An eyeball assessment of the property offers a rough draft diagnosis for drainage issues, but contractors shouldn’t stop there, advised

Ross Richardson, landscape designer, Dunn Lawn & Land, St. Louis, Mo. “Contractors should look at more than what is being asked of them,” he said. “The homeowner is only seeing one issue and you might find another that hasn’t come up.” This is why careful site evaluation should precede drainage solutions, otherwise, what seems to be the answer might spur another problem – in a different area. “You think you’re solving a problem in one spot, but all you might be doing is redirecting it to another,” said James Arch, designer, Impullitti Landscaping, Chagrin Falls, Ohio, describing a common mistake he calls “moving the water around the yard.”

A transit level helps determine site grade so contractors can accurately map out water flow, and soil percolation tests also indicate poor drainage points. By filling a pit with water, contractors can locate slow-straining soil. If a foot-deep pool drops less than 1 to 2 inches per hour, the soil will most likely prevent proper drainage. Besides consulting these quantifiable measures, Arch conducts his own real-time analysis. “Problems are most evident after a big rainstorm, and that’s usually when customers call and say they have a lot of standing water in an area,” he noted. “Instead of me going out to the site later on a beautiful, sunny day to take a look at it, I will wait until the big rainstorm so that I can see the problem firsthand.”

FILTER THE PLANS. Though water might collect in only one spot, there is generally far more than one fix for soppy soil. “The best way to solve any drainage problem is to get the water to run over land where it’s supposed to go,” Eiserman simplified. However, this option is easier said than done. Some situations don’t allow for regrading or creating swales to direct water to storm drains, streets or other community-designated collection areas. “The first thing we do is we get a grading plan,” Eiserman noted. “If it is an old property, we get the plan from the original construction or the most updated plan. If that doesn’t exist, we do a grading plan ourselves, which then goes to the city or community for approval.”

Newly developed areas and urban housing communities often insist that landscape contractors present the board or homeowners’ association with a plan detailing how water will be handled, Eiserman pointed out. Codes vary depending on the location, so designers should check into red-tape requirements before breaking ground. “You also need to discuss all the ramifications with the homeowner,” Eiserman added. “You need to have them understand that you are basically moving water from one spot to another. If they have the conception that you will make it go away, they will be unhappy with the end product.”

Some clients’ expectations aren’t so refined – they are content with a little wet grass. Others want completely dry results. The complexity of the solution can depend on homeowners’ standards, Arch added. “A question we ask a lot of clients is, ‘Is this your forever home?’ That dictates what they are willing to spend to improve a property.” Eiserman agreed that serious clients will drop more dollars into long-term drainage designs. “If they have young children or a yard they like to entertain in, they will be willing to spend money to find out what the problem is,” he figured, adding that budgets can range from $1,500 to $20,000 depending on site size and situation.

And, depending on the location and severity of the wet land, the swampy area might not be a problem, but instead one of nature’s little character flaws – unappealing, but harmless, Deckman said. After all, topography creates personality on properties. “If it is standing water and it is not creating a problem with the house or having a negative impact on the site, it’s not considered a drainage problem – it’s an ecosystem,” he reasoned.

NEW CONSTRUCTION QUAGMIRES. With houses crammed into tightly-woven, planned communities and properties’ lines carefully mapped out to the square foot, most homeowners don’t view poor drainage as an interesting everglade. They don’t have room on their lots to ignore the soggy corner of the yard, so instead they see an eyesore and an inconvenience.

Most often, homeowners discover soaked soil around the foundation of their homes, where inadequately compacted backfill has settled and formed a downward-sloping grade. “A year later, you can see settling in those areas with loose backfill, so you have water at the foundation, which can eventually find its way into the basement,” Arch described. “In those situations we seal the foundation and build up the soil so there is positive drainage away from the structure.” Arch also suggested checking downspout connections to make sure they are tight and water is directed away from the house. “These seem basic, but more often than not, they are where problems begin,” he commented.

Attaching additional piping to the downspout encourages water to flow away from the foundation, and ensuring that piping drains into a lower grade will prevent it from seeping back toward the home. Again, make sure the solution doesn’t recreate the problem. “Where is the water problem and where do you want that water to go?” Arch asked. “Make sure you are taking the water you want to get rid of and getting it to the point.”

However, sometimes the problem doesn’t originate on the property – it comes from the neighbors. Unruly land grades present problems that aren’t so cut-and-dry when back yards collide and the property grades differ. Since water generally gets trapped at the property’s edge, it pools and must be drained with more technical measures. Here, and in situations where water collects in the middle of bowl-shaped back yards or prairie-flat properties, contractors might install a French drain or catch basin, Richardson suggested.

Both options require digging a hole, installing a pipe, and dispersing water back into the soil or pumping it into a designated collection area. While catch basins can pump out water via a sump pump, French drains allow water to seep back into the soil through a perforated, concrete pipe, Richardson explained. “You create a trench, fill the trench with stone, and within the stone is a perforated drain tile – a pipe with slots in it so the water can seep into it and then flow out of it,“ he detailed. “The weakest point where water can flow through is the stone, since there are more openings in that than in the soil.

After the water goes into the stone and into the pipe, it accumulates and flows away.” These options offer drainage solutions when regrading or creating swales in the land – subtle trenches that carry away water – are not feasible options. These methods also might hike up prices, although each situation differs. Besides back-yard clash, homeowners also need to consider their neighbors when installing patios, driveway additions and swimming pools, Eiserman added. He said site adjustments cause most drainage issues on Mariani Landscape’s projects.

“Anything that increases or speeds up the runoff that happens on a site can cause problems,” he said. “All of that water needs to go somewhere. You’ve taken the water, collected it, and now you’re running it to a certain point on the site. Hardscapes create runoff highways in a sense, so when contractors make these additions to clients’ properties, they should notice where water collects and plan for drainage systems if necessary, Eiserman added. After all, the neighbors won’t be so eager to swim in the new pool if they find their own natural version in the form of puddles on their lawn. This is a common mistake. “If you bring your water someplace to where the neighbor wasn’t used to having it, that will bother them,” he said simply.

SLOPE AND SLIDE. Wetlands and wilted plants are sure-fire signs of soil that won’t strain water, but drainage issues are two-fold. Sometimes, water doesn’t sit on top of soil, but instead, it speeds quickly across slopes and causes erosion. Richardson considers slopes masked drainage difficulties. “They aren’t drainage problems, but with drainage issues, they pose erosion problems, which can develop into drainage problems,” he clarified. “Water has an extreme force, even when it moves slowly.

Much how a small stream cut the Grand Canyon, the same thing can happen on a back yard that slopes down toward the house or away from the house so you’re collecting water in one area.” Depending on the severity of the erosion, contractors can opt for a variety of fixes, from retaining walls to vegetation to dry creek beds. While plant material offers an aesthetic answer, the slow-growing groundcover might not offer immediate results to handle extreme situations, Richardson said. Retaining walls offer visual appeal while still taming some wild waters, Richardson noted. “Retaining walls create terraces instead of a slope,” he illustrated. “Water moving over the top is moving in a shorter section instead of one big area, so that breaks up the ability for the runoff to do damage.”

However, this type of construction can require landscape redesign in some cases, he added. In Missouri, retaining walls higher than 3 feet require engineering profiles since they call for reinforcements, he said. For the most part, retaining walls on residential properties don’t need this outside expertise, however. “Typical stone or block wall doesn’t typically need to be approved,” Richardson said. “But check with your community. If a wall is of a certain type or size, it might require a permit before building.”

Furthermore, retaining walls can’t manage drainage problems without the hardware. They, too, need systems to make sure water doesn’t build up behind the walls and collapse the material, Richardson added. “They need to be constructed per a manufacturer’s specification that calls for drain tiles that collect the runoff that may get trapped behind walls, and that can be dumped into a common area or a swale to carry the moisture away,” he said. But looks don’t always win the crown. Slopes might fall into an area of flat turf that gathers water, like one property Arch remembered. “You might have to pump the water uphill,” he mentioned.

This case required a subsurface drainage system with a pump to force water to an appropriate area. Arch’s own property slopes downward and erosion is limited by two swales on either side of the slope that collect water. Some scenarios might call for dry creek beds – essentially, swales filled with rocks or material to slow water’s force. Not the most attractive option, this still controls water flow. If erosion is a problem during construction, contractors should consider using silt fencing to station soil, Deckman offered.

Of course, drainage assessments entail more than the basic ups and downs, and each case presents unique site challenges – its own set of drainage dire straits. Identifying these characteristics and prescribing corrections comes with experience and a panoramic perspective of property layouts, Richardson stressed. “If you are only going to look at one scenario when assessing a drainage problem, you are missing the bigger picture,” he said. “It’s a lot like landscaping. If you are only dealing with the plant around the front door, but you don’t consider the shade trees overhead, you are missing the big picture. If you’re only going to look at the downspouts and determine that’s the problem, you’re missing it. Don’t leave yourself short-sighted.”

The author is Managing Editor – Special Projects for Lawn & Landscape magazine and can be reached at khampshire@gie.net..