California Code, Government Code - GOV § 66462.5

(a) A city, county, or city and county shall not postpone or refuse approval of a final map because the subdivider has failed to meet a tentative map condition which requires the subdivider to construct or install offsite improvements on land in which neither the subdivider nor the local agency has sufficient title or interest, including an easement or license, at the time the final map is filed with the local agency, to permit the improvements to be made. In such cases, unless the city, county, or city and county requires the subdivider to enter into an agreement pursuant to subdivision (c), the city, county or city and county shall, within 120 days of the filing of the final map, pursuant to Section 66457, acquire by negotiation or commence proceedings pursuant to Title 7 (commencing with Section 1230.010) of Part 3 of the Code of Civil Procedure to acquire an interest in the land which will permit the improvements to be made, including proceedings for immediate possession of the property under Article 3 (commencing with Section 1255.410) of Chapter 6 of that title.

(b) If a city, county, or city and county has not required the subdivider to enter into an agreement pursuant to subdivision (c) and if a city, county, or city and county fails to meet the 120-day time limitation, the condition for construction of offsite improvements shall be conclusively deemed to be waived.The waiver shall occur whether or not the city, county, or city and county has postponed or refused approval of the final map pursuant to subdivision (a).

(c) Prior to approval of the final map the city, county, or city and county may require the subdivider to enter into an agreement to complete the improvements pursuant to Section 66462 at such time as the city, county, or city and county acquires an interest in the land that will permit the improvements to be made.

(d) Nothing in this section precludes a city, county, or city and county from requiring a subdivider to pay the cost of acquiring offsite real property interests required in connection with a subdivision.

(e) “Offsite improvements,” as used in this section, does not include improvements that are necessary to assure replacement or construction of housing for persons and families of low or moderate income, as defined in Section 50093 of the Health and Safety Code.