CITY OF SANTA MARIA
Stormwater Basin Policy
August 20, 2024
STORMWATER BASINS
• Basins are used to manage flood
control, by collecting stormwater and
slowly releasing it at a controlled rate so
downstream areas are not flooded or
eroded
• New basins are also considered for
water quality treatment, adhering to
Clean Water Act’s National Pollutant
Discharge Elimination System (NPDES)
regulations, and as implemented through
the State Water Resources Control
Board and Regional Water Quality
Control Boards
POST CONTRUCTION REQUIRED (PCR) BASINS
• Most development projects are required to provide a stormwater detention basin for post-construction flood control, but also stormwater pollution control, per regulations adopted by the Regional Water Quality Control Board • This is to ensure reduction of pollutant discharges to the maximum extent practicable and to prevent stormwater discharges from causing or contributing to a water quality violation
• Typical maintenance includes removing accumulation of sediment, litter, or debris; clearing obstructed inlets and outlets; repairing or replacing damaged components; addressing poor, overgrown, or dead vegetation; and repairing and replanted eroded areas
• Due to reporting requirements to the RWQCB, bioretention basins need to be monitored and maintained, including regular testing of soil and media, and site restoration and erosion control
POST CONTRUCTION REQUIRED (PCR) BASINS
• Requirements to meet increasingly stringent water quality standards pose potential significant long-term costs, should the City assume ownership and maintenance of any additional stormwater basin
• The tasks for addressing stormwater quality exceed and are distinguished from typical landscape maintenance
PROPOSED POLICY
The City shall not accept ownership, nor accept maintenance of any stormwater basins required as a condition of approval for any development project.
An exception to this policy may be made on a case-by-case basis provided the basin serves a public benefit, such as a regional recreation space for use by the general public (i.e. sports field), whose design, configuration, size and public access meets the requirements of the Recreation and Parks Department.
This exception may only be made provided the basin meets the following criteria:
1. The basin does not serve as a stormwater control measure requiring ongoing or perpetual maintenance as identified in a Stormwater Control Plan and is not subject to the post- construction requirements of the Regional Water Quality Control Board (“RWQCB”).
2. The basin is not subject to any other permit from the RWQCB or other regulatory authority.
3. There is a funding mechanism in place to pay for maintenance and operation of the basin, such as being part of a Landscape Maintenance District, Special Benefit Zone, and/or other approved funding mechanism.
OTHER CONSIDERATIONS
• Most newer developments have privately owned and maintained basins:
shopping centers, apartments, etc.
• For single-family development, a homeowner’s association or community facilities district would be established to fund and manage these improvements • Many newer single-family developments are being privately managed as they include more shared amenities, such as pocket parks and community rooms, in conjunction with smaller lots and higher density
• Staff encourages the development of high-quality projects with improvements that would meet all requirements and serve future residents with good community amenities that would be perpetually and effectively maintained over time.
END OF PRESENTATION