Rainwater Resources
What We Do
MHBI provides investigations and recommendations to homeowners who are experiencing issues from the higher volume of rainwater that we are now regularly receiving due to the higher heat load in the atmosphere, and the move to the South by the jet stream. We typically can locate the issues and recommend solutions without deeper forensic inspections or destructive actions. The hard part, if you are not willing or able to perform the repairs or make the necessary changes yourself, is to find qualified companies or individuals to perform the work. We have researched, and provide some links to sites that collect and screen companies for their skills and qualifications, however we do not recommend any specific company, so due diligence is in order before hiring someone.
Types of Rainwater Management
There are multiple tactics to manage high volumes of rainwater that are causing problems on your property, either outside the home or both outside and inside. Note that here, we are only focusing on the issues and solutions on the exterior of home. MHBI is a firm believer that if you solve the water issues on the exterior and "keep the water out" then you do not need to deal with the issues water causes once it gets into the home. Most of the big waterproofing companies only have interior solutions which do not resolve the water problems on the exterior, allowing it in to your home and then pumping it back out, including expensive backup equipment.
What can you do on your property? One or more of the following options may be a solution depending on the grading, soil, size, percent of non-absorptive surface (structures, sidewalk & driveway) and slope of your property and surrounding properties. |
Redirection - The simplest of solutions, re-directing rainwater away from the foundation will reduce the possibility of water intrusion into the home through porous basement wall structures. Extending downspouts and raising the level of the soil around the foundation of the home are the best, easiest, and cheapest ways to move water away from the foundation using slope and gravity to do the work. Use the heaviest fill dirt you can locate when filling voids and raising the level around the foundation, as it is least absorptive. Move away any mulch or topsoil first, fill with the hard packed soil, and then replace the topsoil and/or mulch on top. remember to keep the soil level away from any siding or porous material a minimum of 4-6 inches, where possible, to prevent water absorption into the materials and possibly causing rot in the structure of the home, and promoting insect infestation. Redirecting the rainwater coming out of a downspout through above ground or through underground piping, carrying it to a garden or vegetated hill where it will be absorbed on the way down is an inexpensive way to spread the rainwater over a larger area for absorption.
Rain Barrels - Installing rain barrels to capture and keep 50 gallons or more of rainwater is a simple and inexpensive way to limit the amount of rainwater on the loose coming off the roof of your home. However, rain barrels take some minimum and regular maintenance that you must be willing to attend to. Remembering to use or drain the captured water after a large rainstorm is necessary in order to capture more the next time it rains. While there may be one out there in the marketplace, we have not found a rain barrel which can expand and survive a winter freeze without busting the plastic open and ruining the barrel. So keeping the drain open in the cold winter months or covering the opening is necessary to protect the barrel from a destructive freeze. Rain Garden - Installing a rain garden can be simple or complex depending on the contour of the land allowing for rainwater to naturally enter the lower garden area, or requiring a backhoe to change the lay of the land allowing gravity to move rainwater downhill into the rain garden. Once created, you will have a shallow pool that can collect the excess rainwater that is not absorbed into the soil onto which it falls. In and around the pool will be bushes, flowers, and other plants selected to survive in the garden and help absorb the excess rainwater. Dry (Rainwater) Well - We like to call them Rainwater Collection (and filtering) Pits to separate the confusion with the common definition of a "well" being for permanently holding fresh water. These pits are generally two to four feet deep and are structures placed in soft soil, sand, or loose rock that take on volumes of rainwater during storms, and drain the water slowly to be absorbed into the surrounding soil thru holes in the structure. Some brands of rainwater wells are Recharge Chamber, Storm Tech Chamber, Rain Tank, Eco Rain System, Rainstore, & Flow-Well. Permeable Pavement - Driveways are basically an impervious sheet over absorptive land, so creating a driveway surface that captures, absorbs, or otherwise directs rainwater to a location that can allow the water to return into the soil is typically a complex and expensive process, unless your driveway is higher than the surrounding soil level. Having a rock, gravel, or grass driveway are generally not considered appealing, so designing and installing a driveway and/or sidewalk using permeable pavers is complex and expensive, but people who have them installed claim they actually work in capturing rainwater into the cracks between the pavers and into the rock and soil below. The most commonly installed material design is the Permeable Interlocking Concrete Pavers or PICP, which is just like the name states. The next, but much less common installation is the Concrete Grid Pavers or CGP, which has significant openings between the pavers where sand or grass can be placed. If you spend any time at beaches, you may have seen the honeycomb or waffle grids in the parking lot with sand or grass in between the plastic, steel, or cement grid openings which is one of the most permeable solid surfaces for vehicles. Swales, Berms, & Underground Piping - Using soil, grading, and underground piping to move rainwater away from the home, or from around the foundation and moving it to a more appropriate location on your property such as flower, vegetable, or garden beds, rain garden or rainwater pit is a way to use the land to do the work for you using gravity. Note that municipalities no longer allow homeowners to dump rainwater that falls onto their property into the street using piping thru curb cuts, and some jurisdictions have fines for doing so. Many years ago, a typical way to remove rainwater coming off the roof of a city home was to pipe it into the waste sewer system, and again, that is no longer allowed, and in some cases will cause a sewer backup in the home. Plants & Mulch - Mother nature provides a simple and natural solution to rainwater capture through plants and mulch. Trees and plants draw water out of the ground and their roots split the soil creating air pockets allowing for oxygen and water to reside in the soil. If you think of topsoil created from compost, and wood mulch as sponges, they have a much larger capacity to absorb and hold rainwater, along with restricting horizontal flow of excess water moving over, through, and around them. Tree Planting - As mentioned above, trees provide benefits by having roots that loosening the soil and hold the soil in place where they end up on the surface, and by drawing up water into the leaves for growth and evaporation. Leaves that fall from deciduous trees also provide absorptive mulch if left in place or used in gardens for weed control. |
Resources & More Information
• City of Alexandria Stormwater Fee Information Guide - www.alexandriava.gov/uploadedFiles/tes/Stormwater/SWU_Credit_Manual.pdf
• Arlington County - Stormwater Control for Land Disturbances - Guide
• Arlington County - StormwaterWise Landscapes - List of Contractors
• Chesapeake Bay Trust - List of Contractors - http://cbtrust.org/wp-content/uploads/Contractor-List_Final_011620.pdf Note the link to the CBTrust list changes regularly, so if the link does not work, go to this link and look for the "landscaping professional" contractor.
• Chesapeake Stormwater Network - Guide for a Bay-Friendly Property
• District of Columbia - Stormwater Management Guidebook
• Montgomery County RainScapes Program - www.montgomerycountymd.gov/water/rainscapes
• Montgomery County RainScapes Project Manual
• Montgomery County Permitting - Dry Well Design Drawing & Dry Well Design Specs for Roof Drain
• Town of Chevy Chase - Has Design Calculations Guide - Water Drainage Ordinance
• Prince George County - Rainwater Collection Options
• Maryland DoE - State Stormwater Design Manual
• HomeTips.com - Basic Tasks to Protect Your Home Against Rainwater Damage
• Arlington County - Stormwater Control for Land Disturbances - Guide
• Arlington County - StormwaterWise Landscapes - List of Contractors
• Chesapeake Bay Trust - List of Contractors - http://cbtrust.org/wp-content/uploads/Contractor-List_Final_011620.pdf Note the link to the CBTrust list changes regularly, so if the link does not work, go to this link and look for the "landscaping professional" contractor.
• Chesapeake Stormwater Network - Guide for a Bay-Friendly Property
• District of Columbia - Stormwater Management Guidebook
• Montgomery County RainScapes Program - www.montgomerycountymd.gov/water/rainscapes
• Montgomery County RainScapes Project Manual
• Montgomery County Permitting - Dry Well Design Drawing & Dry Well Design Specs for Roof Drain
• Town of Chevy Chase - Has Design Calculations Guide - Water Drainage Ordinance
• Prince George County - Rainwater Collection Options
• Maryland DoE - State Stormwater Design Manual
• HomeTips.com - Basic Tasks to Protect Your Home Against Rainwater Damage