Is this in addition to a Spanish Immersion program in the RWC district, or is this RWC's first immersion program?

Part of the reason for the difference in the districts' responses may be that Menlo Park is a Basic Aid district and Redwood City is a revenue limit district. Redwood City may receive state funds for students from outside their boundaries attending their schools.
Redwood City's response is the correct one for a variety of reasons.

The Redwood City School District has a Spanish immersion school called Adelante. Web Link

Clarification please. This sounds like it is an immersion program run within the auspices of the existing district schools vs. A disruptive Charter School ? I would hope that the MPCSD will end up with an in-district program as well.

Just responding to the comments: 1) We have two schools, Adelante and Selby Lane offering Spanish Immersion for younger grades and Kennedy school continuing with the Spanish Immersion program for 6-8th grade students. 2) We will add another Language Immersion program - Mandarin Immersion - at John Gill school starting in 2015-2016 school year. 3) We will continue with our other Spanish Immersion programs in addition to adding the Mandarin Immersion program. 4) These are not charter schools, but district lead schools/programs. 5) We receive money per student from the State so this will not be an additional cost for us since we will receive money for each student enrolled which should cover the costs associated with the teacher, classroom supplies, etc. 6) Redwood City School District students will have priority for the school, but if there are spots available, students outside of the district would be welcome to apply for the school.