### Area of a Junction

Hi,
Anyone knows what is the exact default area of a junction and the possible ways to input an another area for the junstion?
Thanks

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#### Replies

• I found the answer for my own question and would like paste it here if anyone needs it in future.
The area of a junction is "0".

Junctions are just connectors which don't have any surface area.
• If the node is empty the area of a junction is the default area of the junction - the smallest area of a junction is not zero

• Hi,
thanks a lot for this clarification.
I was looking for this and I couldn't find this value.
I asked from the author of the SWMM 5.0 and I was told that the default value is 0.

However I now know how to adjust it.

Thanks again.
• void initNodeState(int i)
//
// Input: i = node index
// Output: none
// Purpose: initializes node's surface area, inflow & outflow
//
{
// --- initialize nodal surface area
if ( AllowPonding )
{
Xnode[i].newSurfArea = node_getPondedArea(i, Node[i].newDepth);
}
else
{
Xnode[i].newSurfArea = node_getSurfArea(i, Node[i].newDepth);
}
if ( Xnode[i].newSurfArea < MinSurfAreaFt2 )
{
Xnode[i].newSurfArea = MinSurfAreaFt2;
}

// --- initialize nodal inflow & outflow
Node[i].inflow = Node[i].newLatFlow;
Node[i].outflow = 0.0;
Xnode[i].sumdqdh = 0.0;
}

As you can see above there is a minimum surface area and it is NOT zero - it is normally set by the user or defaults to 12.566 square feet.
• yeah I understood it. Thanks again for helping me to find out the things.
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