Investors & landlords

OK, completed my taxes with the appropriate information and I owe some taxes, a little over $10.  As I was completing my review to E-submit I noticed that some estimated payment vouchers were included.  I don't anticipate my taxes to change as I'm retired so I've already changed my W4 and added extra withholding each month just in case.

- Do I still need to send in these extra payments?  Or is it optional?