---
title: Duluth UDC § 836.04 — Duluth
jurisdiction: duluth
governing_jurisdiction: Duluth
source_url: "https://www.duluthga.net/UDC_ADOPTED_9.8.2025_Amended_7-13-26.pdf"
effective_date: "2026-07-13"
as_of: "2026-08-13"
canonical: "https://www.gwindex.net/code/duluth/836.04"
licence: "CC0-1.0"
---

# Duluth UDC § 836.04

Engineering Study Requirements for Floodplain Encroachments

**Governing jurisdiction: Duluth.** A "Duluth, GA" mailing address is usually NOT in the City of Duluth. Unincorporated Gwinnett is 67.3% of the county's land area and is governed by a different code, a different board and a different permit portal. Resolve the governing jurisdiction before answering any zoning question.


- **Article:** 8 — Environmental Protection
- **Pages in source:** 236–237
- **Adopted:** 2025-09-08
- **Amended through:** 2026-07-13
- **Source:** https://www.duluthga.net/UDC_ADOPTED_9.8.2025_Amended_7-13-26.pdf

## Text

An engineering study is required, as appropriate to the proposed development activities on the site, whenever a
development proposes to disturb any land within the future-conditions floodplain, except for a residential single-
lot development on streams without established base flood elevations and/or floodways for which the provisions
of 836.04 apply. This study shall be prepared by a currently registered professional engineer in the State of Georgia
and made a part of the application for a permit. This information shall be submitted to and approved by the
Planning and Development Department prior to the approval of any permit which would authorize the disturbance
of land located within the future-conditions floodplain. Such study shall include:

235 | P a g e

Article Eight. Environmental Protection

1. Description of the extent to which any watercourse or floodplain will be altered or relocated as a result of
the proposed development;
2. Step-backwater analysis, using a FEMA-approved methodology approved by the Planning and
Development Department. Cross-sections (which may be supplemented by the applicant) and flow
information will be obtained whenever available. Computations will be shown duplicating FIS results and
will then be rerun with the proposed modifications to determine the new base flood profiles, and future-
conditions flood profiles;
3. Floodplain storage calculations based on cross-sections (at least one every 100 feet) showing existing and
proposed floodplain conditions to show that base flood floodplain and future-conditions floodplain
storage capacity would not be diminished by the development;
4. The study shall include a preliminary plat, grading plan, or site plan, as appropriate, which shall clearly
define all future-conditions floodplain encroachments.