The muddy part accounts for a quarter of the total length.

The water part is 2 feet longer than the mud part, which is a quarter of the total length plus 2 feet.

The part above the water is 3 feet.

The sum of the three parts is half of the total length plus 5 feet = the total length.

Then the total length is 10 foot.

Equation:

Full length x

1/4x+ 1/4x+2+3=x

x= 10