Time series data is stored in DSS using the HecTimeSeries function "write":
HecTimeSeries public int write (TimeSeriesContainer timeSeriesContainer)
JAVA
HecTimeSeries.write() returns 0 (zero) for a successful operation. If an error occurred in the Java code, a negative number (usually -1 to -5) is returned. If an error was detected in the DSS code, a large negative number is returned.