Holidays

Holidays are welcomed diversions from everyday life and provide time to celebrate and relax with family and friends.  These diversions are reflected in sewer use patterns, as shown below.  Flow monitoring data from several familiar holidays are displayed in comparison with normal weekday and weekend sewer use patterns.  To a sewer sociologist, a holiday looks much like a weekend.  However, characteristic differences are observed that make each holiday unique.  See what differences you can find and how they compare with your holiday traditions.

These composite hydrographs are interpreted by noting the differences between the average weekend curve and the holiday of interest.  Several interesting observations are noted:

• Higher sewer flows are observed early on New Year’s Day as people celebrate the arrival of the New Year.  The morning rise also occurs later in the day as people recover from the night before.
  
  
• Martin Luther King, Jr. Day and President’s Day are government holidays.  However, many businesses in the private sector remain open.  As a result, the morning rise occurs earlier than a typical weekend as a certain percentage of the people wake at their normal weekday time and prepare for work.
  
  
• Memorial Day and Labor Day are quite similar, both with higher sewer flows during the late morning and early afternoon as people enjoy the holidays.
  
  
• Lower sewer flows are observed during the evening on Independence Day as many people depart to watch local fireworks displays.
  
  
• Thanksgiving Day provides the most noticeable deviation from typical weekday flows, with peak flows occuring around the time of the traditional Thanksgiving meal.
  
  
• Peak flows on Christmas Day are less than those observed on Thanksgiving.  However, increases are observed around afternoon and evening meal times.  Note also the higher sewer flows observed during the early morning hours, a traditional time when Santa Claus is believed to be busy delivering gifts.