Let \( x \) be the number of students from South Springdale High School.
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 sent by all three schools can therefore be expressed as:
\[ x + (x + 5) + (x + 11) = 46 \]
Simplifying this equation:
\[ x + x + 5 + x + 11 = 46 \] \[ 3x + 16 = 46 \]
Now, subtract 16 from both sides:
\[ 3x = 46 - 16 \] \[ 3x = 30 \]
Now divide by 3:
\[ x = 10 \]
Now that we have the number of students from South Springdale High School, we can find the number of students from North Springdale High School:
\[ \text{North Springdale} = x + 5 = 10 + 5 = 15 \]
Thus, the number of students coming from North Springdale High School is \( \boxed{15} \).