What if the water is coming into your basement from below? It’s important to differentiate between water that is coming from drain lines and plumbing, or if the moisture is from groundwater seeping up from the earth below. For cases in which water is entering your home from backed-up drain lines, backflow preventers are in order. Many cities, including Alexandria, offer incentives or partial reimbursement for these installations.
If it’s a matter of groundwater seepage, you will need a sump pump. Sump pumps are generally installed in areas below the finished grade of your basement floor. They are often located in a > 2-foot corrugated pipe or dry well casing. The sump pump is plugged into an electrical outlet and is generally installed with a flotation switch. This flotation switch is designed to turn the sump pump on if there is enough water in the basin to cause the switch to floating. The sump pump is generally installed with PVC piping and a backflow preventer that will carry the pumped water from the basin up the PVC pipe through a hole in the foundation to the outdoors. I would be remiss if I didn’t offer a few additional pro-tips: if you have a sump pump running through a hole in your foundation, ensure that the hole is sealed on the outside with mortar, and sealed on the inside with pest-resistant insulating foam to avoid potential heat loss or pests getting inside. If you have a generator or backup power supply, ensure that the circuit your sump pump draws power from is connected to receive backup power. This can help avoid an unfortunate situation in which a power outage results in flooding.
But now that the water is outside, what now?! Here is where attention to detail is important. The ideal water management system installation will have the water pumped into a gravel bed or dry-well area that can help displace water without eroding soil. Depending on how often your sump pump operates, the location where the water is emitted can also be a great place for water-loving trees, shrubs, and flowers. You’ll want to make sure that you avoid situations in which sump pumps emit near concrete sidewalks. During the winter months, these areas can become icy. It’s also best to avoid directing this to the curb where groundwater drains into stormwater infrastructure. I think of these as examples of missed opportunities to utilize fresh water to irrigate some of your beautiful water-loving plants!
And if groundwater from outside the walls or below the basement floor was not enough, we must also account for rainwater from above. Stormwater requires its own suite of solutions that complement the groundwater solutions. For stormwater, it’s a matter of responsible collection and reducing potential off-site runoff. Given the older infrastructure that we face in Alexandria and throughout other historic neighborhoods of our region along with the increased amount of roads, rooftops, and other impervious surfaces, it’s best to avoid any rainwater from running off your property. Existing stormwater infrastructure is simply ill-equipped to handle it. Mitigating runoff can be achieved by taking multiple steps including having high-capacity rain barrels to hold water until
needed for irrigation, permeable hardscape areas, and uncompacted planting beds and lawns, and rain gardens. Once these systems are installed, runoff from any impervious surfaces you have must be directed into your stormwater best management practices (BMPs) via swales, grading, or downspout, and gutter lines. And when using gutter lines, particularly those that are underground, ensure you have clean-out valves and utilize PVC rather than corrugated pipe so that they can be maintained and cleaned out. These BMPs; rain gardens, permeable hardscapes, bio-retention ponds, swales, dry-wells, exfiltration pipes, etc. have the opportunity to avoid or mitigate potential runoff, which can ultimately lead to flooding.
To recap, often the relationship with water is more about management than outright permanent mitigation. Specific strategies can be implemented in just a few steps with a licensed and properly trained contractor:
- For below-grade water, sump pumps are important. They are devices, generally tied to floating triggers, which pump water up and out.
- The only waterproofing that will matter is exterior waterproofing. Concrete and especially CMU’s (concrete masonry units), such as cinder blocks are permeable. They absorb water and without proper sealing and waterproofing, they can leak water or emit water vapor. This can make for musty basements. Exterior drain tiles collect water against the house and direct it into a French drain installed at the footer of the house.
- By implementing diversion strategies, you as a property owner can responsibly manage your stormwater by keeping it on-site through rain barrels, converting any patios or driveways to permeable surfaces, and maintaining planter beds as part of rain gardens.
At my company, Tactical Land Care (TLC), we utilize CBLP (Chesapeake Bay Landscape Professional) best management practices (BMPs) in conjunction with Interlocking Concrete Paver Institute (ICPI) and Permeable Interlocking Concrete Paver (PICP) principles and design criteria. We find that these protocols are critical in quality assurance for our clients. But that isn’t to say that there aren’t other ways of identifying solutions. I would just recommend that when hiring a contractor, do your due diligence and confirm what materials are selected, what their lifespan is, and whether there are any manufacturer warranties. Also, ask for a written guide for maintenance procedures or schedule follow-up maintenance. Professional stormwater management professionals will adhere to manufacturer specifications and industry standards and should be happy to discuss their installations. Ultimately, we hope that you will embrace more ecologically responsible solutions in approaching the various ways of contending with water in all its forms.
Patrick Moran | CEO Tactical Land Care
Patrick utilizes his passion for the outdoors along with his professional skills as a licensed Landscape and Home Improvement contractor in Virginia and Maryland, as well as a Project Management Professional (PMP) and LEED Green Associate. Patrick has a BA from Yale University, where he studied climate change and its impact on society.