this record is from an area where two very similar Nymphoides species both occur: N. geminata and N. montana. Separating N. montana from N. geminata in a photograph is a challenge, as the defining characteristics are details of seed, size of flowers and whether heterostylous or homostylous.: see sighting 4410122.
From your photo, it could be either species. Abundance is always a challenge for water plants that tend to expand laterally.