maintenance costs of rain gardens/bioretention
A common argument I hear about green infrastructure/low impact development stormwater technologies (such as rain gardens/bioretention) are that the costs of performing long-term maintenance will be too expensive.
Consider the two photos below. One is of a bioretention/rain garden designed to treat stormwater from an urban area and the other is a decorative street planter designed solely for aesthetic purposes. The decorative street planter requires regular maintenance for watering (especially in Colorado), weeding and trash removal. The bioretention/rain garden requires regular maintenance for weeding and trash/debris removal. (A bioretention/rain garden should not need supplemental irrigation if it is planted with appropriate vegetation).
So, which of these cost more? If a municipality or property owner is already paying for landscaping maintenance services for non-stormwater gardens/planters, what is the additional cost of maintaining stormwater gardens/planters? I think the costs will be similar, or perhaps less using rain gardens/bioretention. If, instead, we called these “below grade” decorative street planters, would the same maintenance cost argument be made? Or is the maintenance costs argument simply an attempt to not change the status quo?
Feel free to reply with your thoughts.
Colorado Stormwater Center