Let the number of students from South Springdale High School be represented as \( x \).
According to the problem:
- North Springdale High School is sending \( x + 5 \) students.
- West Springdale High School is sending \( (x + 5) + 6 = x + 11 \) students.
The total number of students from all three schools can be represented by the equation:
\[ x + (x + 5) + (x + 11) = 46 \]
Now, we can simplify this equation:
\[ x + x + 5 + x + 11 = 46 \] \[ 3x + 16 = 46 \]
Next, we will solve for \( x \):
\[ 3x = 46 - 16 \] \[ 3x = 30 \] \[ x = 10 \]
Now that we have \( x \), we can determine the number of students from North Springdale High School:
\[ \text{Students from North Springdale} = x + 5 = 10 + 5 = 15 \]
Thus, the number of students coming from North Springdale is:
\[ \boxed{15} \]