Flow Statistics used to Develop Building Blocks Recommendations for Big Cypress Indicators of Hydrologic Alteration – Environmental Flow Component (EFC) Appendix D Indicators of Hydrologic Alteration – Environmental Flow Component (EFC) Appendix D 2 and 10 year recurrence interval flows Appendix E 2 and 10 year recurrence interval flows Appendix E

Indicators of Hydrologic Alteration – Environmental Flow Component (EFC) Divides the hydrograph into high flow (>75 th percentile) and low flow ( 75 th percentile) and low flow (<50 th percentile) High flows are further divided into Large Floods (10 year recurrence), Small Floods (2 year recurrence) and High Flow Pulses (rise faster than 25% and fall faster than 10%) High flows are further divided into Large Floods (10 year recurrence), Small Floods (2 year recurrence) and High Flow Pulses (rise faster than 25% and fall faster than 10%) Low flows also include Extreme Low Flows (<10 th percentile) Low flows also include Extreme Low Flows (<10 th percentile) Percentile statistics of the low flows for each month are also generated Percentile statistics of the low flows for each month are also generated

ECF Defaults

IHA-EFC Statistics for Big Cypress (33 years)

IHA-EFC Statistics for Little and Black Cypress

2 – year recurrence interval ( year) Bank Full Flow – Flushing accumulated fine sediments from gravel, scouring pools, building riffles, removing vegetation from active channel inundating bars and maintaining channel capacity. Bank Full Flow – Flushing accumulated fine sediments from gravel, scouring pools, building riffles, removing vegetation from active channel inundating bars and maintaining channel capacity. Effective Discharge – Flow that transports the largest amount of sediment when averaged over time. Effective Discharge – Flow that transports the largest amount of sediment when averaged over time.

High Flow Calculations IHA calculates high flow stats based on daily average flows, by default the 2 year and 10 year recurrence intervals. IHA calculates high flow stats based on daily average flows, by default the 2 year and 10 year recurrence intervals. PeakFQ – USGS program to Flood Frequency using log-pearson Type III regression based on instantaneous annual peaks PeakFQ – USGS program to Flood Frequency using log-pearson Type III regression based on instantaneous annual peaks

Big Cypress High Flow Recurrence

Big, Little and Black High Flow Recurrence