REPOET OF THE COMMISSIONER OF FISHERIES. Ill 



supply were brought together, the trouble could then be corrected by 

 devices that would afford an extensive contact with the air. This 

 would require a pumping plant to raise the water, and the plan would 

 probably be best carried out by digging one or more large wells which 

 would increase the volume of supply and gather it convenient for 

 pumping. This, however, would be expensive in first cost, and a con- 

 tinuing expense thereafter, and is not to be recommended. 



The simplest, least expensive, and best plan for increasing and 

 improving the water supply of the station is believed to be to tap 

 Colerain brook and bring its water to the hatchery. This brook rises 

 in the drainage ditches of a meadow, and flows some 2 miles to the 

 Nashua River. It is at present a somewhat depleted trout stream, and 

 its water is to all appearances of suitable quality for fish-cultural pur- 

 poses. Two determinations show it to have a proper content of dis- 

 solved air, which could hardly fail to be the case, since it is a small 

 brook well exposed to the air by its length and the nature of its bed. 

 Shortly before reaching the river it skirts closely the Fisheries reser- 

 vation. The volume of water carried by it is subject to considerable 

 seasonal variation, but is greatest in the winter and spring when most 

 needed, and if carried to the hatchery would probably be sufficient to 

 provide for all the eggs. It could be supplemented by Pennichuck 

 water if necessaiy. The water of all the hatchery wells could then be 

 diverted directly into the ponds — without flowing through the troughs — 

 and at the same time could be aerated and de-aerated considerably on 

 the way. Since the Colerain supply can itself be turned into the ponds 

 from the hatchery troughs, the water of the ponds will be very greatly 

 improved. The artesian wells rising in the ponds themselves can in 

 most cases not be improved, since they scarcely rise above the level of 

 the pond water, and experience may show would be better plugged 

 up. This may apply also to the larger wells rising in the ponds. 



With the Colerain .supply available for the hatcher}^, the water of 

 the reservoir pond could be applied to the fish ponds only, as it is at 

 present in part. It receives considerable exposure to the air in the 

 flume on the way to the ponds. This addition to the water supply of 

 the station is expected to prevent most of the losses now occurring 

 each season. 



Plans and estimates are already available, the route from the brook 

 to the hatchery having been previously surveyed by the engineer's office 

 for the purpose of supplying the hatchery. The project was aban- 

 doned at that time in favor of Pennichuck water, the use of which 

 entails an expense at meter rates and is not intended to be continuous. 



It is interesting to note that the Pennichuck water which supplies 

 the city of Nashua is, at its source in artesian wells, greatly deficient 

 in oxygen and has a marked excess of nitrogen, and would certainly 

 kill brook trout. In its course to the pumping station it is thoroughly 



