[GRASSLIST:7875] Water height vs. lake area using R.fill.dir

[Armando Scalise]

I need to estimate the areas of a set of lakes for differente  water 
height scenarios.

I am using the SRTM 30 DEM and I was hoping to apply r.fill.dir, to get 
the flow direction and water height for given heihg increments.

The documentation for r.fill.in stgates that "The procedure takes an 
elevation layer as input and initially fills all the depressions with 
one pass across the layer".

Unfortunately, there is no specification as to how tis is done.  I have 
searched for the paper describign the algortihm on whihc r.fill.in is 
based "Software Tools to Extract Structure from Digital Elevation Data 
for Geographic Information System Analysis" by S.K. Jenson and J.O. 
Domingue (1988). but I have been unable to find it in the internet.

I need to ask two questions:
 1) is there any other method you would reccomend in addition to 
r.fill.dir to compute  water height/areas ratio for depresions using a DEM?
 2) Anybody has a copy of the above cited paper or a detailed 
description of the algortuhm?

Cheers thanks

Armando Scalise