Wai‘ula‘ula Watershed Plan

Wai‘ula‘ula Watershed Plan

• Background • Watershed condition• Status of plan

Wai‘ula‘ula watershed

headwaters

Intermittent flow in middle and lower reaches

groundwater seep

Current and future land use

Background on watershed plan ....

• focus on nonpoint pollutants • prerequisite for EPA funding of BMPs• MKSWCD lead agency• Carolyn Stewart

lead writer

Phase 1 of Watershed Management plan

• Describe watershed and threats to water quality

• stream water quality monitored with autosamplers and urban grab samples

• Potential BMPs identified

identified impairments• Waikoloa Stream below Waimea Town

– TN and TP • Wai‘ula‘ula stream just above ocean

– TN• adjacent Pelekane stream

– TSS, TN, TP 2 orders of magnitude above standard• nearshore marine waters

– ammonia and algae

Of concern but not measured– pools in intermittent sections of stream– losses due to streambed infiltration

Potential sediment and nutrient sources• forest• urban and suburban Waimea

– Stormwater runoff– septic tanks

• Lalamilo farm lots• grasslands and scrublands

– fire– overgrazing– feral ungulates

• Coastal resort

Stream after a fire (excessive sedimentation)

Potential sediment and nutrient sources• forest• urban and suburban Waimea

– Stormwater runoff– septic/cesspools tanks

• Lalamilo farm lots• grasslands and scrublands

– fire– overgrazing– feral ungulates

• Coastal resort

Original Plan did not meet EPA 9 elements

• Without the 9 elements there is no EPA 319 funding

• Need a rationale for selection of BMPs

• Currently re-writing plan to meet requirements

EPA 9 elements:What must be done prior to applying for funding

• Identify causes and sources of nonpoint pollutants (data limited)

• Quantify load reductions expected for selected BMPs (methodology not mature – using N-SPECT model)

• Have monitoring plan to evaluate if project is successful

N-SPECT model can (?) evaluate sources and pollutant loads with/without BMPs

Priority BMPs identified in draft plan

• conservation plans for farms• improved fire management• improved grazing management• riparian zone and post-burn

restoration

Proposed administrative BMPs identified in draft plan

• institute overlay district that explicity protects riparian areas

• Low Impact Development Outreach• Obtain cesspool information

Current status