The Rimba Raya Biodiversity Reserve REDD Project

the assessment area; and second, an evaluation of communitydependence on such rivers as a source of clean water and theirvulnerability to floods if upstream areas are degraded.Step 1. The Toolkit defines ecosystems important for provision ofwater and prevention of floods as:Cloud forestRidge line forestRiparian or flood plain forestKarst forestPeat forest or peat landFreshwater swamp forestMangrove forestMarsh or other wetland vegetationLakes or other open water bodiesOf these nine ecosystem types listed in the Toolkit, six arepresent in the Project Zone: (i) riparian or flood plain forest, (ii)peat forest or peat land, (iii) freshwater swamp forest, (iv) marshor wetland vegetation (natural and manmade), and (v) lakes orother open water bodies.Step 2. Results of social surveys in the Project Zone (see sectionsG1.5, G1.8.5 & G2.4) indicate that: (i) local communities arefundamentally dependent on the Seruyan river and its tributariesfor the provision of water, protein (fish), and transportationwithin the Project Zone; and (ii) communities are extremelyvulnerable to floods, which are becoming more frequent andsevere as upstream forests are degraded by logging and fires andreplaced by grassland and in the north converted to oil palmplantations following clear-­‐cutting and drainage of peat swamps.The expansion of oil palm plantations into northern sections ofthe Project Zone deserves special mention. Plantations haveeffectively transformed the ecological function of this area froma ‘natural sponge’, which dampened hydrological impacts ofintense rainstorms by absorbing and slowly releasing rain water,to a compacted, rapidly draining source of storm water runoff.One could argue, in a strict sense, that communities are nolonger dependent on upstream ecosystems of the Project Zonefor prevention of floods, since floods are reported to be frequentand severe, implying that, in fact, ecosystems no longer functionto prevent floods. Such reasoning would be inconsistent,however, with the spirit of HCV, since it is clear that continueddegradation of these upstream ecosystems will make a badsituation worse. Very large areas of intact peat swamp forestremain in the Project Zone (c. 27,700 ha; see Section G1.2), andconversion of these areas to oil palm would severely worsen thefrequency and duration of floods suffered by downstreamcommunities.Any and all intact and regenerating peat swamp forest, riparianor flood plain forest, and natural grass land or marshy swampsplay a vital role in the provision of clean water and prevention ofworsening floods. These areas are considered HCV 4.1ecosystems in the Project Zone.HCV 4.2HCV 4.2 aims to identify areas with high erosion risk that must bemanaged carefully to prevent soil erosion or sedimentation ofrivers or open water bodies.72