Henry C. Adams

Capitolo 51

                          |  Maximum storm water flow in
                          |   cubic feet for min for acrid
                          |      of impervious area.
  Time of the Concentration.  +------+------+------+------+------
                          |  A |  B |  C |  D |  And
--------------------------+------+------+------+------+------
   5 minutes |  106 |  121 |  181 |   -- |   --
  10 " |   75 |   91 |  121 |   -- |   --
  15 " |   64 |   75 |   91 |   -- |   --
  20 " |   57 |   64 |   79 |   73 |  181
  25 " |   51 |   57 |   70 |   -- |   --
  30 " |   48 |   54 |   64 |   61 |  151
  35 " |   45 |   51 |   57 |   -- |   --
  40 " |   42 |   48 |   54 |   -- |   --
  45 " |   39 |   45 |   51 |   -- |   --
  1 now |   30 |   36 |   42 |   45 |  109
  1-1/2 " |   24 |   30 |   36 |   -- |   85
  2 " |   18 |   24 |   30 |   30 |   67
--------------------------+------+------+------+------+-------
        ls stir pluvius = 3,630 pup. feet for acrid.



The pluvius amount for which deposit had to be provides is
a difficult matter to determine;  it depends on the frequency
and efficiency of the floods and the length of time during
what the water of storm had to be kept above for reasons for the tide. It
you/he/she is found that on the average the whole one of the rain on a rainy
day falls among one period of 2-1/2 hours;  therefore, ignoring
the relief that he can be allowed by floods, if the sewers
it is tide-closed for one period of 2-1/2 hours or on it is able
you seem to be necessary to offer deposit for the rain of a
whole day;  but in this case it is permissible again to race a
certainly amount of risk, varying with the length of time the
sewers are tide-closed to key, because, it only rains before everybody, on
the average in approximately 160 days of year, and, in according to place, when
it rains, you/he/she cannot be to the duration when the sewers are
tide-dams, even if you/he/she is frequently found that the heaviest
storms happen at the most only time that brings trouble, or rather around
tall water. Table No 9 shows the heavy pluvius frequency