SDWP.6011.6: Approval of Stream Diversion Works Permit Application to Modify Diversion Nos. 156, 209, 232, 142, 168, 267, 255, 187, 177, 145, 243, 144, 236, and 244, Fix Leaks and Provide Habitat Connectivity, East Kōlea, Kaʻaiea, ʻOʻopuola, Nailiilihaele, Hānawana, and Hoʻolawa Streams, Maui, Tax Map Key(s): (2) 1-1-001:042, 50; 2-9-004:004; 2-9-012:029; 2-9-014:001, 004, and 009

Posted on Oct 26, 2023 in Updates

SDWP.6011.6: Approval of Stream Diversion Works Permit Application to Modify Diversion Nos. 156, 209, 232, 142, 168, 267, 255, 187, 177, 145, 243, 144, 236, and 244, Fix Leaks and Provide Habitat Connectivity, East Kōlea, Kaʻaiea, ʻOʻopuola, Nailiilihaele, Hānawana, and Hoʻolawa Streams, Maui, Tax Map Key(s): (2) 1-1-001:042, 50; 2-9-004:004; 2-9-012:029; 2-9-014:001, 004, and 009

Applicant: East Maui Irrigation Co., Ltd.
Landowner: East Maui Irrigation Co., Ltd.; State of Hawaiʻi
Project Summary:

Div. No. Description TMK Stream
156 Install 18-in wide steel plate x 0.6-in high concrete channel and upstream berm lip at low point side to pass all flows up to 0.08 cfs (0.05 mgd) to remain in the stream without providing for connectivity.  If necessary, notch down stream potion of dam lip. (2) 1-1-001:050 East Kōlea
209 Install 18-in wide steel plate x 0.6-in high concrete channel and upstream berm lip at low point side to pass all flows up to 0.08 cfs (0.05 mgd) to remain in the stream without providing for connectivity. (2) 1-1-001:050 East Kōlea
232 Install 18-in wide steel plate x 4.3 in high concrete channel and upstream berm lip(s) at low point across grate to pass 1.8 cfs (1.12mgd). Where necessary, fix leaks in wing wall. (2) 1-1-001:042 Kaʻaiea
142 Install 18-in wide steel plate x 1.5-in high concrete channel and upstream berm lip at low point side across grate to transport all flows up to 0.36 cfs (0.23 mgd). (2) 2-9-014:001 ʻOʻopuola
168 Install steel plate to cover 20% of grated area with 1-in high concrete channel and upstream berm lip(s) at low point across grate to transport 20% of all flows and provide connectivity and recreational uses. (2) 2-9-014:001 Nailiilihaele
267 Within ditch, increase ditch intake invert 0.75-in above top of dam such that all flows up to 1.8 cfs (1.12 mgd) pass over dam to provide for habitat connectivity and recreational uses. (2) 2-9-014:001 Nailiilihaele
255 Within ditch, increase ditch intake invert to be 1.8-in higher than bedrock elevation at top of waterfall such that all flows up to 3.6 cfs (2.32 mgd) go over waterfall to provide for habitat connectivity and recreational uses. (2) 2-9-014:004 Nailiilihaele
187 Maintain wetted path over dam with invert notch (18-in-wide x 9.1-in deep) in concrete dam to transport all flows up to 5.2 cfs (3.36 mgd) to provide for habitat connectivity and recreational uses.  Close sluice gate.  Add weir in ditch behind gate with a height to match top of notch. (2) 2-9-014:004 Nailiilihaele
177 Increase pipe diameter to 8-in to prevent clogging and maintain a continual flow of water to meet downstream riparian uses. (2) 2-9-012:029 Hānawana
145 Install steel plate to cover 20% of grated area with a 1-in high concrete channel and upstream berm lip at low point across grate to transport 20% of all stream flows to provide for recreational and aquatic habitat uses. (2) 2-9-014:001 Hoʻolawa
243 Install 8” PVC piping at 0.29% slope and valve from Lowrie ditch to ensure 0.7 cfs (0.45 mgd) continues for recreational uses & downstream habitat [no connectivity] when sluice gate is closed. (2) 2-9-004:004 Hoʻolawa
144 Install steel plate to cover 20% of grated area with a 1”-high concrete channel & upstream berm lip(s) at low point across grate to transport 20% of all streamflows to provide habitat connectivity, recreational, riparian, and aquatic habitat uses. (2) 2-9-014:001 Hoʻolawa
236 Create 18-in wide x 3.25-in deep channel at low point in bedrock to ensure all flows up to 1.2 cfs (0.78 mgd) continue downstream from the intake to provide recreational, downstream habitat, riparian, and aquatic habitat uses.  New weir in ditch to match top with top of new channel in bedrock.  Baffle to limit high flows into ditch remains. (2) 2-9-014:009 Hoʻolawa
244 Install steel plate to cover 20% of grated area with a 1-in high concrete channel and upstream berm lip at low point across grate to transport 20% of all flows to provide downstream habitat connectivity, recreational, riparian, and aquatic habitat uses. (2) 2-9-014:001 Hoʻolawa

File Size: 6.3 MB
Comment Deadline: November 25, 2023