Amenitizing water retention in new community design
Amenitizing water retention is not a new concept, especially with every square inch of land coming at a premium these days. My goal as a land planner and community designer is to help developers address requirements while enhancing the lifestyle opportunities of the neighborhood. I believe balance is possible, but only with a clear vision from the outset.
Temperature control is also key. Maintaining moderate temperatures will reduce energy costs and positively impact the community. In my international work, building orientation is prioritized to maximize efficiencies in circulation and density. Careful building alignment forms the basis for the rest of the site plan. Working outward from individual buildings or units challenges our thinking about how to target required sustainability goals, especially water runoff. Inverting the visioning process like this has yielded some creative solutions.
In California, much of my work involves urban infill sites, so the opportunity to create these open swaths of passive retention is limited. Instead, site water is tied to municipal stormwater management, so there’s pressure to manage it well so we don’t overtax the system. In a recent design in Merced, we used a permeable road surface as a channel, creating an urban swale that links to the municipal system. This was more expensive upfront, but it addressed the city’s water concerns so well that it helped expedite approvals, which more than made up for the additional investment.
One common myth is that retention areas are unusable. Sometimes, even when we have the right retention calculations, a new law or municipal regulation will mandate even more retention area (as much as double). Developers tend to think we just lost buildable land, but I prefer to focus on gaining a valuable amenity. Open space has become one of the top amenities sought by consumers. While we certainly try to incorporate pocket parks and outdoor features in new communities, one of the best opportunities is in retention. Dedicated retention basins can be aesthetically pleasing and functional as water features, but that’s not our only option. Incorporating sections of rolling grass, terraces, and shallow water management methods can create amazing open spaces that are truly functional when residents really want to use them.
During periods of heavy rain, people are not inclined to be outside in the grass anyway, so we can’t worry about that. These retention areas do not have to be “usable” as an amenity 100% of the time. When the time is right (sunny and dry), these retention features become truly functional amenities that will create a more engaging community experience.
When paired with a traditional amenity like a club, pool, or park, passive retention is an excellent way to design for sustainability. Natural swales, green spaces, and channels keep water on-site, and native vegetation naturally filters runoff before it reaches the basin. Consider bringing in a consultant to design additional filtration so you can use retained water for irrigation and create a complete cycle of water reuse on site.
A modest club paired with a grassy swale and small retention basin provides a subtle but effective way to manage water in this built to rent community.
If cost was not a factor, cistern water storage on-site would be the ideal solution. But to keep development costs down, we consider other options, such as the urban swale described above. This helps us effectively address regulations while managing the overall budget, which is a win-win for everyone involved.
Recently, California has seen rising temperatures and unpredictable water levels due to sporadic drought followed by heavy rains. Our goal is to be aware of these climatic realities as we begin the conceptual visioning exercise for each new community. That way, we can work our way outward—from the individual homeowner all the way to the surrounding environment. Traditional retention design methods paired with some innovative advancements will help us manage water more effectively.
As a bonus, you’ll create a built environment with free, open space that offers light, air, and views to surrounding residences. We know that green space and vegetation are also keys to temperature control. Maintaining moderate temperatures will reduce energy costs and positively impact the community. A modest club paired with a grassy swale and small retention basin provides a subtle but effective way to manage water in this build-to-rent community.
This article was featured in Green Builder Magazine’s May/June 2024 issue.
