Looking around, a number of widths exist for these systems, and installing what is called pre-cast units would start at about 10k$ for the smallest (4ft in diam

Looking around, a number of widths exist for these systems, and installing what is called pre-cast units would start at about 10k$ for the smallest (4ft in diameter), and go up from there (see EPA paper below for additional details). Maintenance costs are said to be really low in what I could find (1000$ a year or so), as maintenance (emptying the trash) can be done by one vacuum truck in 30 minutes. So it may be a better choice for systems that are there to last rather than nets, but nets would still be best for temporary sites. http://www.water-research.net/Waterlibrary/Stormwater/hydrodynamic.pdf http://www.water-research.net/Waterlibrary/Stormwater/hydrod...