INFOSHEET 6, DECEMBER 2017

AT A GLANCE This information sheet has been prepared for Lake size: 3400 ha Te whānau to summarise information Catchment area: 12160 ha about: Elevation: 279 m • research and monitoring occurring on Lake Average depth: 31 m Rotoiti. Deepest point: 93.5 m • projects occurring on, and adjacent to Lake Rotoiti, particularly efforts to reduce the The eastern part of the lake sits in the north of the impacts of land use on lake water quality. Ōkataina caldera (volcanic depression) and has geothermal springs. The western half – a drowned It will be reviewed and updated annually. valley, Te Awa-i-Takapuwhaia – was formerly an outlet for Lake .

NAME MEANING WATER QUALITY MONITORING Lake Rotoiti, the shortened form of Te Roto-Whaiti-i- The Regional Council carries out regular monitoring kite-ai-a--i-Ariki-ai-a Kahumatamomoe or "the of Lake Rotoiti. This includes: small lake discovered by Īhenga". • Swimming water quality – Three sites measured from October to June. Any health IWI warnings are posted on the Regional Council Ngāti Pikiao, Ngāti Te Takinga, Ngāti Hinerangi, Ngāti and Toi Te Ora Public Health websites. Tamateatutahi, Ngāti Kawiti, Ngāti Hinekura, Ngāti • Scientific – Three sites measured monthly for Rongomai, Ngāti Te Rangiunuora, Ngāti Makino. clarity, algae, phosphorous and nitrogen. Result articulated as an annual Trophic Level Index or TLI.

Monitoring Sites Source: LAWA website Water Quality Trend

4.7

4.2 Declining

3.7

3.2 1998 1999 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Annual Result Target Improving

WATER QUALITY TREND LAKE ACTION PLANS Water quality has improved since 2004, reaching the Draft and Rotoiti Action Plan 2009 - target TLI on 2013 and 2014. Since then, water This Plan comprises 17 actions to improve the water quality has not improved. Delays with sewerage quality in Lakes Rotorua and Rotoiti. It includes reticulation means that further improvement can be projects and actions for the regional council, district expected to occur in the future. council and catchment landowners. Download from: http://www.rotorualakes.co.nz/vdb/document/78 WATER QUALITY STATUS 4 The Trophic Level Index 3.5 ACTION PLAN PROJECTS (TLI) is used to give an 3 Includes, but is not limited to: overall picture of the Project Status 2.5 health of Lake Rotoiti. Sewerage reticulation is in place for Completed 2  /Okawa Bay and Okere

1.5 Falls/Otaramarae/Whangamarino. TLI target not met. For 1 the 2016/17 year, the TLI Sewerage reticulation is proposed via a In progress was 3.8, which is over the 0.5 combined scheme for Rotomā and East target of 3.5. 0 Rotoiti (Gisborne Point and Hinehopu).

Target 2016/17 Result New Regional Council rules in place for Completed TE ARAWA MONITORING septic tank discharges and other types of Te Arawa Lakes Trust is embarking on a project to onsite wastewater treatment systems within lakes catchments. measure and monitor the cultural health of Lake Rotoiti using indicators that are more meaningful to Ohau Channel Wall – Impact Monitoring Ongoing us. This may be based on the following: Kōura, kākahi, smelt and trout monitoring has also been carried out to • Can I swim here? look at the long-term effects on the wall. • Can I gather food here? Information sheet: We will also continue working with Dr Ian Kusabs http://www.rotorualakes.co.nz/vdb/doc ument/300 who monitors kōura populations in our lakes using tau (bracken fern bundles).

WHERE TO FIND MORE INFORMATION www.tearawa.iwi.nz Te Arawa Lakes Trust www.rotorualakes.co.nz Rotorua Te Arawa Lakes Programme www.lawa.org.nz Land Air Water Aotearoa