{"subjectId":"sepa-gauge-234257","seriesUrlPattern":"/api/v1/series/{metricId}--{subjectId}.json","seriesCount":1,"observationCount":912,"series":[{"metricId":"river-flow-monthly-mean","subjectId":"sepa-gauge-234257","unit":"m³/s","periodKind":"month","count":912,"from":"1951-10-01","to":"2026-09-01","sourceId":"uk-sepa"}]}