The local ECI number is 821-9478. They are physically located in Bryan, but also serve many surrounding counties.
As someone posted above, you may also want to inquire with Brazos Valley Rehab. You would likely receive a higher frequency of services with this option, as many kids with ECI are seen for speech 2x/month. Their number is 776-2872.
In order to qualify for speech services through your local district, your child's delay must be so significant that it is considered a disability, thus the formal evaluation. The evaluation would need to be done and the initial ARD held on or before their third birthday, unless you refer after they turn three. Some districts have a screening process to help you know if formal testing is needed or not. You can find out more about the special education process here:
http://framework.esc18.net/