106 TYPICAL QUEENSLAND LAGOON 
The banks of the lagoon are cleared of timber for a distance 
of about 8 chains from the water’s edge. There are several 
tributary creeks feeding the lagoon, but only two of any size. 
The area of the lagoon when full, is 186 acres, of which 
about one-third consists of shallows less than 13 feet deep 
at high water, that is, when the lagoon is full. 
The greatest depth of water is 55 feet, and the estimated 
total capacity is 1,000,000,000 gallons. 
The lagoon contains abundant growths of common water 
weeds which Mr. Bailey, the Colonial Botanist, has been good 
enough to identify, and a list of which will be found in the 
Appendix I to this paper. Many of these weeds die, and 
rise to the surface whenever any considerable and sudden 
rise of water takes place in the lagoon. Some of these 
plants are undoubtedly responsible for a proportion of the 
colour and odour of the water. Mr. G. ©. Whipple, in his 
work on the “ Microscopy of Drinking Water,” states that 
Myriophyllum, of which there is abundant growth in this 
lagoon, “‘ possesses a natural odour that is strongly vege- 
table, and at times almost fishy,” this odour is imparted to 
the water whenever the plants die or are crushed and broken. 
I have myself observed this, and I have also found this 
plant to cause a sensible increase in the colour of water in 
which it was placed. 
There is practically no flow of water in the creeks feeding 
the lagoon except after heavy rain. There are many pools 
more or less deep in the bed of the main creek in which 
abundant growths of Spirogyra, etc., exist after dry weather 
has continued for a short length of time. These growths 
are washed into the lagoon whenever any flow of water takes 
place in the creek. 
The average total rainfall at ie lake per annum, for the 
past five years, was 33.93 inches. (For 1904-5 rainfall see 
Appendix IT.) 
The water discharged into the lagoon by the creeks is, 
tor the first day or so after heavy rain, highly charged with 
organic matter evidently of vegetable origin, and is also 
highly colcured, but after flowing for some little time it 
gradually improves in quality until, having run for, in some 
cases four days, the creek water is in some respects purer 
than the bulk of the water contained in the lagoon. 
(Appendix III.) 
