38 Fish and Game Warden. [Bull. No. 1. 



the water is too deep for a fish pole, a cork or light float may 

 be attached to the string holding the thermometer bottle, so 

 that it can be found and raised for bottom temperature readings 

 when desired. Ponds that are fed by springs or from under- 

 ground sheets of water, and those that are filled by pumps, 

 have a lower temperature (other conditions being equal) than 

 those that are supplied directly from creeks, open ditches or 

 from surface drainage. The average temperature of shallow 

 ponds is higher than that of deeper ones under similar condi- 

 tions.* 



ready to fill the pond. 



After the dam or dike has been finished and the bottom of 

 the pond has been put in proper condition to be filled with water, 

 the owners are usually anxious to see the new pond area fill 

 up with water either from natural drainage or such other 

 sources of water supply as the locality may afford. It would 

 really be better in many cases to allow the new dam and pond 

 area to stand and settle for a few months or even a year. How- 

 ever, this is not necessary, as it is possible to fill new-made pond 

 basins as soon as they are finished,! Before the water is turned 

 onto the ground that is to serve as the bottom of the newly-made 

 pond it should be carefully examined for sandy, gravelly or 

 porous places. Just what special thing should be done to put 

 the bottom in proper shape to hold water depends upon the 

 nature of the material that goes to make up the bottom. Some 

 instructions and a number of suggestions have already been 

 given (in Part I) regarding the special treatments of pond 

 basins in getting them ready to serve as good water-tight bot- 

 toms. 



FILLING THE POND. 



When the time to fill the pond with water actually comes it 

 is always advisable, when it is possible to do so, to allow the 

 pond to fill slowly and gradually. In the case of the so-called 

 sky ponds that are filled with storm and flood waters this 

 matter cannot be so well regulated and the pond may fill up 

 in a few hours' time. Under such circumstances the filling 

 process should be carefully watched and the overflow, or spill- 

 way, kept open so that any sudden accumulation of superfluous 

 water could escape without doing damage to any part of the 

 pond structure. The writer happens to know of a few instances 

 where this matter of the first filling of ponds with flood waters 

 was not watched as it should have been. The overflow, or 

 spillway, became clogged with trash and the water was forced 

 over the new-made dams, which were eaten away by the un- 

 controlled waters in an incredibly short period of time. 



* Actual temperatures will be discussed in Part III of this Bulletin. 



t See how Baily pond was filled as soon as the earthworks were 

 completed. Page 33, Part I. 



