Rain, Rain Go Away

Landscape Storm Preparation: Do This Before It Rains

In Hawaii we are blessed with good weather most of the year. However, come November and we sometimes find ourselves under water. If you’re not careful, this can be quite literally! Here are some important tips for preventing flooding in your home.

1. Grading away from Homes.

Proper grading is the best insurance against flooding. Grading in construction terms is the work of ensuring a level base, or one with a specified slope. Construction workers would grade before laying a house’s foundation or putting down a road. The same should be done before starting a landscape. Grade so water flows away from structures. Try to minimize channeling water into a concentrated stream, especially if you’re directing it into a downhill neighbor’s property. Consider trapping water on your property in a rain garden (sand trap). Even if your garden is already established, there are subtle changes a landscaper can make to improve grading on your property.

2. Consider the soil.

If you live along the coastline and have sandy soil or on Tantalus, a cinder cone, you probably don’t need to worry about standing water, since your soil is very porous. Areas like Kuliouou or Waimanalo with heavy clay soils, become saturated very quickly with heavy rains and grading becomes much more important. When grading can’t be done to move water, then an under ground drainage system may be required.

3. Think about equipment.

Use a transit, laser level or clear aquarium tubing filled with water to ensure drain pipes are installed properly. Water flows downhill and pipes need to have enough slope. Pumps need electricity that may not be available during storms. Drain grates and underground pipes require maintenance and occasionally clog.

4. Moisture sensors are amazing.

Many states now require that new sprinkler systems are installed with moisture sensors. Moisture sensors turn controllers off during rainy weather. If you don’t have a moisture sensor, many sprinkler clocks have seasonal adjustment features where you can reduce the amount of water by a percentage instead of reprogramming each station.

5. Maintain the border!

When practical, install a 12” – 18” wide gravel or rock maintenance strip around the foundation of your house. Set sprinkler heads the same distance from the foundation to keep the house walls dry. Maintaining this border around your property will also reduce the amount of insects and rodents that have access to your home. If you need help deciding whether this is something for you, give us a call!