failed bioretention system

Why is it that the smallest things can turn out to be the biggest problems? When bioretention systems fail (which can happen for a variety of reasons), site owners are often left with a mess. Engineers blame the installation, installers blame the material suppliers, and suppliers blame the design. To top it off, regulators can come off as unsympathetic while they try to do their job – requiring that the system meet water quality standards it was designed to provide. In the end, the failed system often has to be completely removed and reconstructed causing a lot of pointed fingers as the dollar signs start adding up. Worse yet, occupancy permits can be delayed or businesses disrupted by restoration work that involves damaging the (typically) finished landscape with heavy equipment, dump trucks, and material storage.

How Reconstructing Bioretention Systems Damages Surrounding Landscape

Let’s say we have to reconstruct a 2,200 sf bioretention system that has failed (one that is large enough to treat runoff from a 1 acre drainage area). Between the excavating equipment, 25-30 dump trucks to remove materials, another 25-30 dump trucks to bring new materials in, and a laydown area for the new materials to be stockpiled – the damage to the site would be extensive. The rebuilt bioretention system may look great, but the costs and site impact will be extensive.

But – what if there was a different way to revive a failed bioretention system that didn’t require the cost and chaos of complete removal? What if, instead of removing and replacing 100% of the non-functioning system, the same restoration could occur with 95% less disturbance?

An alternative to a complete replacement with 95% less site disturbance

FocalPoint is a high-performance bioretention system (pictured below). While most traditional systems treat runoff at 2-5 in/hr, FocalPoint provides the same benefits while moving water through the system at 100 in/hr – which is 95% faster. This allows the same volume of water to be treated as the original system, but in a much smaller space. Now, instead of removing the entire 2,200 sf system in the example above, it’s possible to simply remove 175 sf directly adjacent the overflow structure to install a FocalPoint system.

This option would only require a mini-excavator to remove a portion of the old system and a small skid steer to load two dump trucks instead of the 25-30 trucks required to completely remove the old system. All the new materials would be delivered in super sacks, so no landscaping would be damaged by piles of materials. Instead of removing all the plants, only the plants in the repair area would need to be removed and transplanted upon completion. Depending on the reasons the original system failed, the pre-existing ponding area and the underdrain may both be used with the new FocalPoint System as well.


If you’re dealing with a failed bioretention system and finding no easy answers, ask yourself these three questions:

  1. Is the cost of complete reconstruction of the system too high?
  2. Is the potential for disturbance of the business or construction site significant?
  3. Would a quicker repair benefit the site owner?

If any of these questions are true, give FocalPoint a try (pictured below). Our team of designers will work with you to reconfigure the existing system and find a solution that works for your site. There’s no cost for the evaluation, and our team is ready to help you resolve what is usually a very uncomfortable situation for everyone!

bioretention system