[paytonc]

I'll posit a water-pipe history of why new money flowed to north Raleigh into the 1990s, and then into west Cary:

- The first part of RTP to be built was its north end, adjacent to where Durham had water pipes. These offices were closer to US 70 than I-40.
- North Raleigh rapidly filled in up to Strickland by 1990; north of Strickland, Falls Lake water quality regs limit density. (Hence, Raleigh's big growth pushes in the mid-90s were Brier Creek and Wakefield/Falls River, at the NW and NE reaches of the buffer.)
- Cary opened its Jordan Lake water treatment plant in 1993. Before that, it bought water from Raleigh, so its water lines extended from the east. Note that Jordan Lake is west of Cary, which made it possible for...
- Cary extended water service to the west so that Wake's end of RTP could have city water. That enabled RTP to grow towards Cary, and Cary (and Morrisville) to suburbanize next to RTP.