34 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



ciently protect them from overflow, but it is advantageous to allow a 

 safe aiuouut of washing to pass into them. 



II. On the beds of branches or creeks. — Ponds made on the 

 beds of branches and creeks will constitute a larger number than any 

 other class. They will prove most valuable for growing carp, but will 

 require much care in the construction of the dam and the overflow. 

 They will not attain to the highest value unless the inflow and outflow 

 of water is screened. Every one who has tried can estimate to some 

 degree the trouble this involves. Whenever it rains the volume is so 

 increased that it is nearly impossible to strain it through screens. 



The only way to control it absolutely is to go above the head of the 

 pond and cut a wide, shallow ditch around the side of the pond and 

 turn the freshets. This will be impracticable in many ponds, but in 

 some cases where plows can be used it can be done with a moderate 

 outlay. 



III. On MEADOW-FLATS. — Pouds built on meadow-flats by the side 

 of branches or creeks can be made entirely safe from freshets. I greatly 

 favor this as well as the following class : On many streams where it 

 would be impossible to build manageable ponds of Class II, large areas 

 of comparatively level land are found which would make excellent ponds. 

 Ponds of this kind would have a dam or dike running down the side 

 of the stream and, turning at right angles from it, run to the hill-side. 

 Now, to get water into this pond, you have to go up the stream until 

 you get 4 or 5 feet of fall. When this point is found, obstruct the 

 run with a log or some piling and cut a ditch along the hill-side with 

 very slight fall (1 inch to 20 feet), running the water nearly level. 

 By the time you get down to the head of the pond you are some dis- 

 tance up on the hill-side, away from the old run. If the stream is flat 

 and the fall insufficient to answer this purpose, it may be practicable 

 to make the obstruction above a tumbling dam, 2 or 3 feet high, 

 by using more logs and piling. The sand filling in behind will make no 

 difl'erence, as the dam is put there for the sole purpose of civing j^ou 

 that much more fall to supply the pond below. With a pond of this 

 kind (and they may often be made) there is no danger of overflow at 

 any time. The supply ditch, made chiefly with a plow, will only con- 

 vey a given amount of water to the pond, and the rest will fall over 

 your log obstruction or tumbling dam^ and pass down the creek. The 

 long dam extending alongside the stream should not be built too close 

 to the old run, as craw-fish will work under it and high water may cut 

 it away. It should be quickly set in cane or Bermuda grass. 



IV. By THE SIDE OF MILL-RACES. — By the side (on the lower side) 

 of mill-races, frequently occur sites well adapted to the construction of 

 fish-ponds. Such races are quite common in the middle and western 

 counties, and they often reach a long distance. On the lower side, be- 

 tween the race and the old bed of the stream, level or comparatively 

 level tracts of land from one to four acres in extent are often found. 



