Maintaining Recharge to Maintaining Recharge to Springs and Seeps Springs and Seeps Downgradient from Downgradient from

Residential Developments Residential Developments

An Analysis From Bodega Bay, An Analysis From Bodega Bay, CaliforniaCalifornia

Main PointsMain Points

• Challenge: End calls late during environmental reviewChallenge: End calls late during environmental review

• Challenge: Design characterization and mitigation monitoring Challenge: Design characterization and mitigation monitoring program sufficiently robust to allow for changes in the project program sufficiently robust to allow for changes in the project or in the hydrogeologyor in the hydrogeology

• Critically Important: Use of multiple lines of evidenceCritically Important: Use of multiple lines of evidence

• Challenge: Evaluate to precisions of 1-3 gpmChallenge: Evaluate to precisions of 1-3 gpm

• Expect: Findings that both prior-season’s rainfall and wet-dry Expect: Findings that both prior-season’s rainfall and wet-dry epicycles affect wetlandepicycles affect wetland

• Challenge: Prepare for monitoring which may stretch over 10-Challenge: Prepare for monitoring which may stretch over 10-15 years15 years

Water Budget ResultsWater Budget Results

• Dry Year:Dry Year: 10.5 acre-feet (5 inches/acre)10.5 acre-feet (5 inches/acre)

• Normal Year:Normal Year: 26.0 acre-feet (12.5 26.0 acre-feet (12.5 inches/acre)inches/acre)

• Wet Year:Wet Year: 36.2 acre-feet (17 inches/acre) 36.2 acre-feet (17 inches/acre)

ConclusionsConclusions

• Embed the ground-water professional early in all Embed the ground-water professional early in all assessments of wetlands and riparian habitats.assessments of wetlands and riparian habitats.

• Multiple lines of evidence are needed to validateMultiple lines of evidence are needed to validate

• Multiple lines of evidence are needed for Multiple lines of evidence are needed for resilience of mitigation monitoringresilience of mitigation monitoring

• Prepare for project durations of 10 to 15 yearsPrepare for project durations of 10 to 15 years