﻿HYDROLOGY 
  OF 
  NEW 
  YORK 
  

  

  411 
  

  

  Geologically 
  the 
  main 
  Mohawk 
  lies 
  largely 
  in 
  the 
  Hudson 
  river 
  

   shales 
  and 
  schists. 
  The 
  tributaries 
  to 
  the 
  north 
  flow 
  across 
  the 
  

   Trenton 
  limestone 
  into 
  the 
  unclassified 
  granites 
  and 
  gneisses 
  of 
  

   the 
  Adirondack 
  region. 
  To 
  the 
  south 
  the 
  tributaries 
  flow 
  across 
  

   the 
  Hamilton 
  shales 
  and 
  upper 
  and 
  lower 
  Helderberg 
  groups. 
  The 
  

   headwaters 
  of 
  Schoharie 
  creek 
  — 
  the 
  principal 
  tributary 
  — 
  lie 
  in 
  

   the 
  Catskill 
  group. 
  

  

  Discharge 
  measurements 
  of 
  East 
  Canada 
  Creek. 
  This 
  gaging 
  

   station 
  is 
  located 
  at 
  the 
  masonry 
  dam 
  of 
  the 
  Dolgeville 
  Electric 
  

   Light 
  & 
  Power 
  Company, 
  about 
  seven 
  miles 
  from 
  the 
  mouth 
  of 
  

   the 
  stream. 
  Readings 
  of 
  the 
  depth 
  on 
  the 
  crest 
  are 
  taken 
  twice 
  

   a 
  day 
  and 
  the 
  mean 
  used 
  in 
  computing 
  the 
  discharge. 
  As 
  at 
  the 
  

   other 
  stations 
  herein 
  discussed, 
  a 
  record 
  is 
  also 
  kept 
  of 
  the 
  run 
  

   of 
  the 
  water 
  wheels 
  and 
  the 
  elevation 
  of 
  water 
  in 
  the 
  tailrace. 
  

  

  The 
  dam 
  is 
  of 
  rubble 
  masonry, 
  19 
  feet 
  high, 
  and 
  has 
  a 
  flat 
  crest 
  

   6 
  feet 
  wide. 
  It 
  is 
  190.25 
  feet 
  long 
  between 
  the 
  abutments. 
  The 
  

   following 
  cut 
  shows 
  a 
  section 
  of 
  this 
  dam 
  : 
  

  

  Fig. 
  31 
  Section 
  of 
  dam 
  on 
  East 
  Canada 
  creek 
  at 
  Dolgeville. 
  

  

  