How to Check if a Property Is in a Floodline: Municipal Flood Maps, City by City

To check whether a property is in a floodline, start with what is already on record (the title deed, approved building plans and the township layout plan), then look at the municipality’s online map viewer, then ask the seller. Only a few municipalities publish floodlines online, and where nothing is published, a floodline study is the only reliable answer.

This guide covers where each municipality publishes flood information, what those maps cannot tell you, and when you need an engineer.

Buying land near a river, or planning to build on it? We determine the floodline for the site, or check an existing one, before you commit.

Floodline determination

Step 1: Check what is already on record

The township layout plan. Section 144 of the National Water Act requires township layout plans to show the 1:100-year floodline. If the property is in a township established since the Act came into force, the layout plan approved by the municipality should show it. Older townships may not.

The title deed and conditions of approval. Some municipalities record flood restrictions against the title. Cape Town’s floodplain policy, for example, can require a notarial deed of restraint when floodplain land goes through a land use application, and building plans endorsed with the floodlines.

Approved building plans. Plans approved near a watercourse often show the floodline the municipality relied on. Ask the seller for them, or request them from the municipality’s building control office.

Step 2: Check the municipality’s map viewer

These are the public sources we found in October 2026:

Municipality	What is published	Where
Johannesburg	50-year and 100-year floodline layers on the City’s map server; the description refers to the Klip River and Klipspruit catchments	eServices Online Maps
Tshwane	A “Tshwane Priority Floodlines” layer; no return period is stated	Tshwane GeoHub
eThekwini (Durban)	“100 Year Flood Plain” and D’MOSS layers; the flood plain was captured between 1985 and 2012	GIS Map Viewer and open data
George	1:50 and 1:100-year floodlines for the Schaapkop, Meul and Gwaing rivers	George GIS portal
Cape Town	No floodline layer; watercourses, wetlands and drainage catchments only	City Map Viewer

Cape Town. Floodlines are held by the City’s Catchment, Stormwater and River Management branch, or determined by the developer for an application. The map viewer shows watercourses and wetlands, which tell you a line may apply, but not where it falls.

Ekurhuleni, Nelson Mandela Bay, Buffalo City, Mangaung, Polokwane, Mbombela, Stellenbosch, Drakenstein, Knysna, Bitou and Sol Plaatje publish no floodline layer that we could find. Nelson Mandela Bay has a static 2015 map image showing 50- and 100-year lines, and Knysna’s viewer shows river development buffers. Ask the municipality’s stormwater or town planning department whether a floodline has been determined for the reach of river near the property.

Step 3: Know what a published map cannot tell you

A line on a public map is a starting point, not an answer:

• It may be old. eThekwini’s 100-year flood plain layer predates the April 2022 floods. In March 2025 the Mayor said the 2017, 2019, 2022 and 2023 floods exceeded the 1:100-year flood in parts of the city, and that the floodlines are being revised.
• It may not say what it is. Some layers state no return period, date or source.
• The catchment may have changed. Upstream development, new road crossings and blocked culverts raise flood levels after a line is drawn.
• It may not match the method the municipality now requires. Cape Town, for example, requires floodlines to be based on the energy level rather than the water surface, which puts the line higher on the bank.
• It says nothing about stormwater flooding. Many flooded homes are nowhere near a mapped river: in the May 2026 Cape Town floods, the City described affected structures in “low-lying flood-prone areas, including wetlands and stormwater corridors”.

Our post on the lines that control building near a river explains the other boundaries (the regulated area, the 32 m distance and municipal buffers) that can affect a property even outside the floodline.

Step 4: Ask the seller

Questions worth asking about any property near a river, stream or low-lying ground:

• Has the property or the street flooded, and when?
• Have any insurance claims been made for flood damage?
• Has the insurer added a flood excess or exclusion? Insurers have raised excesses or withdrawn flood cover in some flood-prone areas, and a property that cannot be insured can be hard to bond.
• Are there approved building plans for every structure, and do they show a floodline?
• Is there a floodline study for the property or the township, and how old is it?

Step 5: Know when you need a floodline study

You need a site-specific floodline determination when:

• you are buying land to develop, subdivide or rezone, and the floodline decides how much of it is usable;
• you plan to build or extend near a watercourse and the municipality has no line for that reach;
• the only line available is old, undated, or drawn before major changes in the catchment;
• a lender, insurer or municipality asks for one.

For a buyer, bank or insurer who needs the flood exposure of a single address rather than a planning floodline, our property-level flood risk scoring gives return-period depths and the evidence behind them.

See our floodline determination service, or send us the property details and we will tell you what is already known about the site and what is still needed.

This post explains the documents and map viewers listed below as they stood in October 2026. Municipal data changes, so confirm with the municipality before relying on it.