Stormwater commission upholds staff: deck and patio not part of building footprint in floodway appeal

The Metro Water Services Stormwater Management Commission on Feb. 6 denied an appeal by homeowner Justin Van Dam over whether a raised deck and adjoining patio at 3407 Springbrook Drive count as the home’s building footprint under Metro Code 15.64.170.

The commission’s decision upholds staff’s interpretation that the deck and patio are not part of the building footprint for the floodway prohibition that states, “no such existing structure located in the floodway shall be enlarged or expanded beyond its existing height or building footprint.” The denial means Van Dam must pursue other routes — such as a variance — only if the commission’s interpretation were reversed.

Why it matters: The ruling preserves a narrow reading of “building footprint” used by stormwater staff to limit new or enlarged structures in mapped floodways. Commissioners said the interpretation is intended to prevent new structures that increase flood risk in complex drainage basins such as the West Fork and Middle Fork of Browns Creek and the culvert system near Interstate 440 and Interstate 65.

Van Dam, the property owner, told the commission he was asking only to treat the existing deck and patio as part of the home’s footprint so he could build a compliant addition without further harming the floodway. “I have no intent of impacting the floodway,” Van Dam said, and argued that federal flood-insurance and assessor records show the deck and patio have been treated as part of the house footprint in public records.

Stormwater staff and counsel argued that the Metro regulations and the stormwater management manual define building/structure for flood-plain management as a “walled and roofed building” and that decks and ground-level patios are structurally independent features excluded from a building footprint for this code section. Stormwater staff said the Metro code’s purpose is to prevent new construction in the floodway and to limit enlargements to buildings except in narrowly defined post-casualty scenarios.

Commission discussion focused on three differences of treatment across Metro departments: (1) the assessor’s public parcel sketches and tax records, which may include attached impervious surfaces when reporting building area; (2) stormwater fee measurements, which count impervious surfaces such as roofs, driveways and patios for billing; and (3) the stormwater/floodplain code and manual definitions that apply to construction in floodways. Commissioners said those records’ differing uses do not change the commission’s task: to interpret the stormwater code for floodway permitting.

Several commissioners noted the thin margin between acknowledging an existing noncompliant condition and permitting a future enlargement that could raise flood risk. Commissioners also urged that, if the appellant wishes to proceed, he should bring full pre‑ and post‑development plans so the commission and staff can evaluate impervious area, finished-floor elevations and required mitigation measures. Staff and commissioners said even if the deck/patio were regarded as footprint, the property’s finished-floor elevation—about 490 feet on the existing elevation certificate—lies below the base-flood elevation cited in the hearing (about 492 feet), meaning any compliant addition would face substantial elevation and mitigation requirements; staff noted a target finished-floor elevation near 496 feet with freeboard requirements.

The commission voted to deny Van Dam’s appeal of MWS’s interpretation of Metro Code 15.64.170, upholding staff’s view that the requested work would require going through the variance and permitting process rather than being treated as an enlargement within an existing building footprint. Chair and commissioners praised Van Dam’s presentation but said overturning staff interpretation in this matter would risk inconsistent application in future cases.

Votes at a glance Motion: Deny the applicant’s appeal of Metro Water Services’ interpretation of Metro Code 15.64.170 (building footprint in the floodway). Motion moved by: Commissioner Simpson. Motion seconded: (second recorded; name not specified in transcript). Outcome: Motion carried. (Vote announced as “aye; any opposed? Seeing none; any abstain? Seeing none.”)