Lake Washington School District forecast: enrollment to fall about 9.7% by 2034 as smaller birth cohorts move through grades

Lake Washington School District leaders on Jan. 27 heard a forecast from Flow Analytics that projects district enrollment will decline from 30,039 students in October 2024 to approximately 27,129 by the 2033–34 school year, a drop of about 2,900 students (9.7%). The presentation came at a district study session attended by board members, district staff and consultants from Flow Analytics.

Flow Analytics senior population geographer Alex Brosh said the drop stems chiefly from smaller birth cohorts that began appearing after 2016 and from a reduced ratio of children born to district residents who later enroll in kindergarten. “So what we see in this chart is … our forecast for the middle scenario was 18,892 students, so our forecast for kindergarten was 9 fewer than actual, which gives you an error of 0.5%,” Brosh said in describing forecast accuracy and methods.

The forecast’s core findings and context: Flow prepared three scenarios (low, middle and high). Under the middle scenario the district’s total enrollment falls to about 27,129 by 2034. Brosh said births to district residents dropped from an average of roughly 2,560 per year (2011–2016) to as few as 2,117 in 2022, and that the kindergarten-to-birth ratio (the share of children born who enroll in district kindergarten five years later) fell from about 0.92 pre-pandemic to roughly 0.82 and is modeled to stabilize near 0.87 in later years.

Flow also presented student-generation rates (SGRs) by housing type: a single-family unit in Lake Washington generates on average about 0.615 K–12 students, while multifamily averages about 0.092 students per unit. Kent Martin, Flow’s director of data analytics services, and Brosh noted that the district and local planners identified roughly 9,200 housing units planned, proposed or under construction over the next decade; about 83% of those are multifamily, 9% townhomes and 8% single-family. Brosh cautioned that multifamily buildings vary and that SGRs rise if a development has more two- and three-bedroom units or income-restricted affordable apartments.

The presentation separated resident enrollment (students who live in an attendance area) and building attendance (students enrolled at each school, including transfers). Flow reported about 3,329 nonresident students enrolled in Lake Washington programs in 2024 (1.1% of enrollment) and roughly 3,535 intra-district transfers (students attending a school other than their neighborhood school), an intra-district transfer rate of about 11.9%. Brosh and district staff said choice programs and available capacity have influenced transfer patterns and that the out-of-district transfer rate had edged up from about 0.9% the prior year to 1.1% in 2024.

Board members pressed the consultants on specific assumptions and data gaps. Director Stewart asked whether the out‑of‑district transfer figure had changed historically; Brosh said comparing across time is possible but is complicated when attendance-area boundaries have shifted. Director Guthrie asked whether forecasts use headcount or FTE; Brosh said forecasts use October headcount and that districts convert headcount to FTE for budget purposes (Flow excludes students with 0 FTE, such as full‑time running start participants, from some internal calculations). Director Laliberte asked whether Flow can separate net migration from enrollment choice; Brosh replied that available data do not allow separating those components reliably and that the K‑to‑birth ratio reflects both migration and capture rate.

District staff and Flow identified follow-up items rather than formal decisions. Staff said they would work with city and county planners to clarify which prospective housing projects include affordable units and would review transfer-tracking processes to better measure choice transfers in and out of the district. Melissa Davita, the district’s interim director of financial services, was introduced as the staff member responsible for incorporating enrollment numbers into budgeting.

Superintendent John (introduced himself during the meeting) thanked Flow and staff and emphasized that the forecast will inform capital, staffing and budget planning. “We take a lot of pride and we really value working towards understanding the data because of what it means, all the way down to the classroom level,” he said.

The consultants emphasized model limits and year-to-year revision: Flow said it is more confident in 1–5 year projections than in the 5–10 year horizon and that yearly updates use the latest births, population and development data. Brosh noted the district’s forecast accuracy for the previous year’s middle scenario was within 0.4% of actual district enrollment, a point the consultants used to justify continuing to use cohort-component models combined with grade-progression ratios.

No formal votes or policy actions were taken at the study session. Board members said the forecast and its scenarios will be used in upcoming budget and facilities discussions, including capacity planning at the secondary level. District staff and Flow recommended annual monitoring of birth cohorts, housing development details (bedroom mix and affordability) and transfer trends to update forecasts and guide capital and staffing choices.

The study session concluded with the board adjourning; staff said the forecast will be folded into the district’s budget and planning cycle and revisited at future study sessions.