The Department of Environmental Services (DES) has recently begun to require systems for stormwater retention to be installed on both residential and commercial properties. This requirement is sometimes met with Flow-Through Planters, Cisterns, etc. (“Planters” as referenced below) They may be attached to a building, freestanding, or buried in the ground. These systems contribute to the operation of a building and are accessory to its function. They are much like other equipment such as furnaces, heat pumps, french drains, air conditioners, etc. ancillary to the operation of a main building. They may also project from main or accessory buildings like balconies or platforms. They are not provided for in the Zoning Ordinance. This advice addresses the issue of placement of these systems (planters).
Relevant ACZO Citations:
- Section 32.D.3.a – “No building or structure, or addition thereto, other than walls or fences, shall extend into a required setback area, yard or court; except that…the following unenclosed uses may extend therein no more than four (4) feet but not nearer than five (5) feet to any property line: Balconies; eaves, trim and fascia boards and similar architectural features; platforms and terraces.”
- Section 32.D.3.b – “Air conditioning units are permitted in required side and rear yards, provided that they are in no event less than eight (8) feet from any side lot line or ten (10) feet from any rear lot line. However, air conditioning units screened with fence or vegetation may encroach into a required setback or yard, where it is located no closer than eight (8) feet to any front or rear lot line, and no closer than five (5) feet to any side lot line.”
Stormwater planters and similar features built to meet the stormwater quality requirements of DES should be treated, for placement purposes, either as projections from buildings (when attached to a main or accessory building on the lot) or as utility features similar to air conditioning units (when constructed as a separate structure from the other buildings). Stormwater planters are considered attached when they are fastened to the building or constructed as part of the foundation. When stormwater planters are projections, they may extend no more than four (4) feet into any required yard setback but not nearer than five (5) feet to any property line. When planters are separate structures, they may be located no closer than five (5) feet to any side lot line or eight (8) feet to any front or rear lot line. When stormwater planter walls are eight (8) inches or less above finished grade, irrespective of whether they are projections or separate structures, they may be located within any required yard or setback.