Systems and methods for detecting a drain standpipe height for a washing machine appliance

A washing machine appliance comprising:

• a tub;
• a basket within the tub;
• a pump assembly operable to flow wash fluid from the tub;
• a controller in operative communication with the pump assembly, the controller configured to store instruction, that when executed, causes the controller to execute operations, the operations comprising:
• initializing an operating cycle of the washing machine appliance;
• activating the pump assembly to flow a first predetermined depth of water from the tub to a drain standpipe following initializing the operating cycle of the washing machine appliance;
• calculating a first drain rate following activating the pump assembly to flow the first predetermined depth of water from the tub to the drain standpipe;
• activating the pump assembly to flow a second predetermined depth of water from the tub to the drain standpipe following calculating the first drain rate, wherein the first predetermined depth of water is different than the second predetermined depth of water;
• calculating a second drain rate following activating the pump assembly to flow the second predetermined depth of water from the tub to the drain standpipe;
• determining a height of the drain standpipe based on the first drain rate and the second drain rate;
• and
• adjusting the operating cycle of the washing machine appliance in response to determining the height of the drain standpipe based on the first drain rate and the second drain rate, wherein adjusting the operating cycling comprises modifying a drain profile of the pump assembly during the operating cycle.