UNH Specialists Teach Residents About Landscaping at Water’s Edge

Freedom – July 9, 2008 — The Ossipee Lake Alliance, in association with the Ossipee Conservation Commission and Green Mountain Conservation Group, hosted UNH Cooperative Extension educators Jeff Schloss and Sadie Puglisi at Camp Calumet in Freedom on June 21 for “Landscaping at the Water’s Edge: An Ecological Approach,” a presentation based on their book of the same name, which teaches waterfront property owners how to use landscaping to solve problems with runoff and erosion.

“We have a situation where some people look at landscaping and say, ‘that’s the problem,'” said Schloss, a professor and water resources specialist. But landscaping can be the solution, he said, and an important one at that—over 80 percent of plants and animals on the endangered species list spend some of their lives on the shoreline.

Schloss explained that some processes that negatively impact water quality occur naturally before any land development. From April to October, one maple beech tree on an undeveloped lot can produce five pounds of sediment, 0.03 pounds of phosphorous and 1,000 cubic feet of runoff. With development and the introduction of impervious surfaces (which speed up the runoff process), that jumps to 18 times the sediment, nearly seven times as much phosphorous, and five times the runoff.

“And it’s not just what happens to that one acre lot—we can multiply that by lots and lots and lots,” he said.

While some processes are unavoidable, he urged property owners to focus on “what you can do to protect and improve water quality using the benefits of vegetated landscape.” The impact can be even more severe in New Hampshire, where watersheds are relatively small and surrounded by steep slopes.

“Here, no matter where you are in New Hampshire, you’re going to have some impact on the receiving water,” said Schloss. Further, he explained that just a teaspoon of toxic material can disrupt an ecosystem – one teaspoon of malathion (an insecticide) in 775 gallons of water affects bluegill, while the same amount in 1,447 gallons affects rainbow trout. The toxin can throw off an entire ecosystem, even if it only affects smaller creatures.

“These things are like the sheep of the water,” explained Schloss.

Without them to eat the growing vegetation, things can quickly get out of control. Responsible landscaping at the water’s edge can help prevent runoff and its negative effects on your lake’s ecosystem. Schloss recommends that waterfront residents determine their objectives, then create a zone beginning at the shoreline; some examples include protecting wildlife habitat, removing sediment or nitrogen, mitigating floods, moderating water temperature, or stabilizing banks.

He suggests installing a 150-foot or larger buffer “to really get a good amount of water protection.” The goal should not be to eliminate weeds completely – they help absorb phosphorous and can create spongy soil good for flood mitigation. Schloss emphasized that vegetative buffers don’t have to compromise your waterfront view. Layering vegetation maintains a view and, by creating an environment much like Mother Nature would, facilitates natural processes like transpiration, evaporation and infiltration through forest duff.

The plants’ roots stabilize soils and prevent erosion, while forest duff and soils act as sponges for nutrients and toxins. Further benefits: Higher shrubs, trees and plants provide shade to prevent the spread of invasive species like milfoil while simultaneously discouraging geese from taking up residence on your beach.

To tailor a buffer to your property’s specific needs, Schloss uses a technique called “following the flow,” a thorough examination of where runoff enters and exits the site. He suggests observing all sources of contributing water, where runoff from impervious surfaces flows, and where the runoff eventually enters the water body. Also, look at erosion: sheet flow (bare areas), rills (often caused by impervious surfaces – “It doesn’t take a lot of coverage to really create these problems,” he said) – deep rills and gullies.

Talk to your road agent to prevent off-site road runoff, or work with neighbors to stop roof runoff. On your site, examine the effects of driveways, boat ramps, footpaths, compacted surfaces and gutters.

“These are all things, as you begin to design your landscaping, you really want to know about,” he said.

Then, using this information on flows, water sources and erosion, create a design to slow or re-direct runoff. As for dealing with the issue, Schloss uses the following techniques: diversion (re-route runoff from steep areas into vegetated areas), interruption (break the flow to slow velocity), spreading the flow over a flat, vegetated area, increasing groundwater recharge, and protecting the shore area with a riparian buffer.

“The more buffer area you can grow out, the better,” he said.

Swales and berms (bumps that keep the water from going further downhill) can be a useful technique for interruption and have been used successfully in Chocorua. Waterbars can slow runoff, while an infiltration trenches and rain barrels can help with roof runoff. Rain gardens capture and soak up storm water.

Other ways Schloss recommends to slow runoff include plunge pools/dry wells (“We’re actually spreading the water as well as slowing it down,” he said), a plunge pool and trench system, and infiltration steps.

“As water runs off, it gets absorbed through the gravel,” he said of the steps.

Schloss added that the more you can meander and turn the water around, slowing its velocity and throwing water off, the better. To stop existing drainage from steep slopes, Schloss suggested using geotextile material (from coconut fibers and organic materials) to stabilize the area. He also said to minimize imperviousness and use vegetation instead – not only is it nicer to look at, but it also takes little time and effort.

Schloss concluded by revisiting his initial scenario. By adding a 50-foot forested buffer and infiltration trenches to the one-acre lot with the maple beech tree, he was able to trim runoff to 1,500 cubic feet, phosphorous to 0.06 pounds, and sediment to 13 pounds.

“Two simple things you can do can bring about tremendous improvement,” he said.

Everything we do affects the water Agricultural Resources Educator Sadie Puglisi introduced her “10 principles of what you can do while designing your landscape to protect your water quality.”

“A well planned landscape can stop water pollution,” she said. “And if you really plan it out well, a landscape is going to create stabilization.”

Landscaping can increase property values and your interaction with your environment.

“Landscape really makes your land more enjoyable for you,” she said.

1. The plants will also take part in transpiration, absorbing water and releasing it through leaves – and off your property. Vegetation creates obstacles for water flow, while the right kind of soil can be a form of protection. “Soil is our friend, but it can sometimes be our enemy,” Puglisi warned.

Because nutrients in soil can be harmful if they make it into your water, Puglisi’s first design principle is to protect and improve your property’s soil quality. In Carroll County, soil tends to be sandy: “You might want to add some organic materials to your soil,” she suggested. These decomposed materials are high in nutrients and the ability to hold water, Puglisi said, adding that 3 to 5 percent organic matter is ideal for a healthy soil system.

Leave or create a duff layer and prevent compaction from humans (people, cars) or nature (rain) – you want air in your soil spaces to water. UNH Cooperative Extension runs soil tests for residents to check potassium and phosphorous contents and pH levels, which Puglisi explained should be between 6 and 6.5 so your soil can release nutrients into plants.

“It’s almost like having a whole plate of food but no fork,” she said of an unhealthy pH. “These will tell you what to put into your soil and how much – you don’t want too much, which will run into the water.”

2. Use variety and vegetative layers. Puglisi recommends starting your design in the water—consider lily pads and cattails. Then work your way out, using groundcovers (sedges, grasses), shrubs under 10 feet, large shrubs, small trees and a few large trees over 25 feet.

3. Select the right plant for the right spot. Puglisi urges property owners to think about where wet areas pop up in the spring and whether a plant is viable in that spot. Also, think about the future – you don’t want a plant to be problematic when it’s full-grown. “You’re going to have to take them all out, which exposes the soil, and it starts all over again,” she said.

4. “Use plants to reduce the force and slow the flow of water,” she said. Leaves intercept rainfall, dense plantings collect and use water, and tall grasses and groundcovers will slow runoff velocity.

5. Maximize the amount of vegetative buffer, which will absorb nutrients, pesticides and water while protecting your investment in waterfront property by preventing shoreline erosion. “You want low maintenance vegetation,” said Puglisi. “Nature makes layers naturally… so just let it go.” But remember that your buffer doesn’t end at your beach: “Your entire yard is a buffer. It’s you that’s protecting that lake,” she said.

6. Minimize impermeable surfaces. “Think about adding some of your sidewalks and driveways right into your landscape and having them look natural too,” she said.

7. Rethink the size of your lawn “because not everybody needs to have gorgeous, expansive lawn,” said Puglisi. “As the water’s coming down, it hits the lawn, it kind of slows down the water…so you do want a small lawn.” She said the “heavy, dense roots” of grass can help with runoff, but New Hampshire’s very low potassium levels can make a thick, healthy lawn difficult to obtain without damaging fertilizers and insecticides.

“Getting there may not be the best for water quality,” she said. However, there are viable options for “low-input lawns,” including fescues.

8. Design for low input – allow airflow, create diversity, add organic matter and use the right plant. “With different plants comes different soil environments below,” she said. “That way nature can check itself and balance itself out.” As a result, everything in the soil will become more diverse, and good bugs will outnumber the bad. Also, avoid the use of pesticides.

9. Design a low-maintenance landscape for longevity, not an overly ambitious landscape to keep up with the neighbors or chase an unobtainable ideal.

10. Your actions on land directly affect the water body. “Remember that everything that we do does affect the water,” stressed Puglisi. Additionally, she suggested an 11th principle: “Don’t work in a vacuum. Work with your neighbor.” Because you probably have the same goals, landscaping together – merging buffers and layers – may help you achieve them faster.

Keeping these principles in mind, Puglisi recommends dividing up the planning process to make it less intimidating. Start with a topographic map of your area and a soil map, both of which are accessible online.

Then create a base plan on paper and mark building footprints, utilities and your septic system. Sketch out steep, wet and eroded areas, areas, then add your driveway, swales, walkways and anywhere water accumulates. Make notes regarding sunlight, wind, invasives, and your view to the water. Also, take an inventory of the plants currently on your property and decide what you like and don’t like.

Don’t even think about what you’re supposed to have. Think about what you like,” she said. “It doesn’t matter what is expensive and ornamental and meant for your lawn.” Draw what to keep on your plan: “All of your wants and desires go onto that paper,” said Puglisi.

Finally, draw up a conceptual plan with “rooms” for an herb or vegetable garden, recreation, woodlands/wildlife habitats and other uses. Then begin one room at a time to simplify the landscaping process, which doesn’t have to be overwhelming.

To go into the topics of landscaping and protecting water quality in more depth, visit http://extension.unh.edu. Copies of Landscaping at the Water’s Edge: An Ecological Approach” are available through the Web site.

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