Water Shed Protection Initiative Lake Lifilikatabu Rehabilitation Varirata National Park
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WATER SHED PROTECTION INITIATIVE LAKE LIFILIKATABU REHABILITATION VARIRATA NATIONAL PARK Table of Contents I Locality Map 3 1.0 Introduction 4 2.0 Current Situation 5 3.0 Project Intent 5 4.0 Site Specific Data 6 -8 5.0 Execution Plan 8 6.0 Deliverables & Replenishment Benefits 9 -11 7.0 Stakeholders and Beneficiaries 11 8.0 Project Sustainability 11 9.0 Financial Proposal 12 10.0 Program of Works 13 11.0 Project Management & Administration 14 Annex –A- Photographs 15 – 16 General Data, Precipitation to Water Shed Protection Initiative 17 - 26 UNDP PARTNERSHIP| WATER SHED PROTECTION INITIATIVE, VARIRATA NAT. PARK - 2 - Map Papua New Guinea PROJECT LOCATION Plate 1 – Google Map of Varirata National Park Project Site UNDP PARTNERSHIP| WATER SHED PROTECTION INITIATIVE, VARIRATA NAT. PARK - 3 - 1.0 INTRODUCTION Water Shed Protection Project – At Lake Lifilikatabu, Varirata National Park (VNP), Sogeri CP The degree, to which water precipitates, hits the ground, runs off and infiltrates into ground or flows directly into waterways to reach the oceans and then evaporates into the atmosphere to repeat its cycle is basically the dynamics of natural hydrological cycle. In the context of this initiative, a supply side exists within the ground water reservoir of the VNP while the demand side exists at the lower discharge end of the water shed area. Naturally people build communities near water sources which are usually at the transitional zone or at the discharge ends of water shed areas. In this scenario, the communities located on the Transitional zone are Rauna 1 & 2, Rauna 3 & 4 while the 17Mile to 14Mile, 9Mile and Lower Laloki areas are located on the Discharge zone of this Water Shed Model. Communities located along the Transitional zone have limited space for agriculture or farming due to the rugged and steep terrain and occurrences of massive basalt boulders and hard rocky surfaces. This condition provides favourable permeability for aquifers and stream flows as evident from road side stream flows. Communities at the lower Discharge zone enjoys favourable expanse of grazing land, agricultural farming land where soil remains relatively moist almost all year round due to their close proximity to the Laloki River System. The VNP receives very good rainfall of over 2,000mm/yr with an average annual temperature of 24.4°C at the height of 800m ASL. This climatic condition makes it less susceptible for rapid evaporation from open lake system and evapotranspiration from vegetation and exposed soil. The evidence of natural aquifers within Recharge, Transitional Zones and the ever flowing Laloki River System within the lower Discharge Side are clear indicators of the existence of a water reservoir located at a higher altitude. More so the evidence of natural stream flows and river systems originating from the massive belt of basalt rock formation within the VNP further suggest the abundance of this renewable water source located deep within the VNP rock formation. One of the most spectacular natural formations within the VNP is the twin natural lake system which is separated by a 15 meter wide natural dyke; with one lake system approximately 500mm above the other. This natural phenomenon allows the ebbing of higher lake system to recharge and the lower lake system and when this system reaches its overflow limit, it spills over into the natural drainage system and discharges into the streams and rivers further below. By understanding the natural environment and habitat of this lake system and the fragile aquatic ecosystem it supports; at the water-air interface, lake-floor environment as well as understanding the geological infiltration potential of the lake’s base stratum, an intervention protocol geared towards maximising water retention could be developed. Therefore the objective of this Project is to increase the lake retention volume, build hydraulic pressure within the lake to promote good soil infiltration and ultimately increase the underground water storage capacity of the ground water reservoir. The Scope of the exercise will be limited to dredging and de-sludging the lake floor from consolidated mud, sandy-silt sludge and tree branches and vegetation debris that have accumulated on the lake floor over a very long period. UNDP PARTNERSHIP| WATER SHED PROTECTION INITIATIVE, VARIRATA NAT. PARK - 4 - 2.0 CURRENT SITUATION – LAKE SYSTEM The current situation is that the entire twin lake systems have built-up sludge levels within 500mm below their water-air interface. The sludge depth extends 1.5m below the 500mm sludge level and this equates to total sludge volume of V = 1.5m D x 200m L x 20m W = 6,000 sq.m, the total combined lake volume to be created within this project scope. Plate 1. Photo of one of the Lake System: 3.0 PROJECT INTENT The Intent is to increase the total volume of the combined lake system adequate to accommodate 6,000 cubic meters of fresh water which should be available at its maximum level during the high precipitation periods from December to April. During the low precipitation period from May to November, it is expected that the lake volume will decrease by 30 – 50% of its total holding load, thus allowing a moderate ground water movement. This is necessary to keep the soil pores open until full circulation resumes when more precipitation occurs. The project implementation strategy will comprise of a mechanised operation methodology where a stringent site operation protocol will be employed to ensure minimum harm to the environment. Agency responsible for the park shall monitor all operational aspects during the course of the project implementation period. UNDP PARTNERSHIP| WATER SHED PROTECTION INITIATIVE, VARIRATA NAT. PARK - 5 - 4.0 SITE SPECIFIC DATA DEMAND SIDE Location Varirata National Park Sub_district Sogeri District Kairiku Province Central Province VILLAGE CODE Varirata Latitude 5° 49' 42'' S Longitude 144° 41' 01'' Hight from Mean Sea Level (in meters) 700 Village 20 Population Cattele Paopulation Nil A Catchment Area in sq. km (of the Watershed) 1 B Type of land use Agriculture in sq. km 0 Industrial in sq. km 0 Domestic in sq. km 0 Public Utilities in sq. km 0.1 Others in sq. km 320 Total Sq. km. 1,063 C Average annual rain fall in mm 2,438 D Number of RainY daYs 60 basaltic lava, ignious E General GeologY of the area rock forms F Attach a copY of location map (google) G Attach a copY of location Photo H Location of nearest Dug Well (m) 0 UNDP PARTNERSHIP| WATER SHED PROTECTION INITIATIVE, VARIRATA NAT. PARK - 6 - Plate 2. SUPPLY SIDE: Water Retention – Lake System Plate 3. DEMAND SIDE – Ground Water seeping out from rock formation and used for laundry, Bathing & irrigation. Sites in Plate 4 below is located directly beneath the Twin Lake System, VNP. UNDP PARTNERSHIP| WATER SHED PROTECTION INITIATIVE, VARIRATA NAT. PARK - 7 - Plate 4. DEMAND SIDE – Roadside vehicle washing using ground water to generates cash income by the Local Land Owners. 5.0 EXECUTION PLAN The execution plan and major scope of works are as follows: 5.1 Mobilise to site and carry out Topographic survey and digital terrain modelling of the two lake systems, and then proceed to carry out civil design works for approval by CEPA, 5.2 Install temporary shoring up works to the lake edges, where dredging equipment will operate on, 5.3 Build temporary earth filled ramps into the lake and commence dredging, 5.4 Transfer and dispose all sludge material dredged from the lake floor at sites specified by the Park’s Ranger, 5.5 Strengthen Lake edges to the near-side according to the approved design, 5.6 Clean up the area, replant damaged grass/lawn section within the Visitor viewing areas, 5.7 Demobilise, and 5.8 Handover and Project Close UNDP PARTNERSHIP| WATER SHED PROTECTION INITIATIVE, VARIRATA NAT. PARK - 8 - 6.0 DELIVERABLES – REPLENISHMENT BENEFITS UNDP PARTNERSHIP| WATER SHED PROTECTION INITIATIVE, VARIRATA NAT. PARK - 9 - The deliverables and the Demand Side are as follows: 1. Increased lake retention volume by 300% from the current estimates of 2,000 cubic meters to 6,000 cubic meters. This will result in increased hydraulic pressure exerted on the lake floor creating new flow lines in the soil pores and more so opening up clogged flow lines and ultimately recharging the ground water reservoir. 2. Tangible gains will include constant seepage through aquifers at low altitudes, within the transitional and discharge zones. See Plate 5 and 6 below, examples of what to expect when the proposed underground reservoir increases in hydraulic pressure within the reservoir: The ground water exiting from the rock formation is located directly under the Lake System UNDP PARTNERSHIP| WATER SHED PROTECTION INITIATIVE, VARIRATA NAT. PARK - 10 - 3. The calculated Potential Lake Retention Volume per year is 14,000 cubic meters of fresh renewable water. 4. Other beneficiaries from this Water Shed Protection Initiative at the Demand Side includes: Plate 7. Grazing land – Located at Adventure Park 14-Mile Plate 8. Laloki River – Flowing down at 17-Mile UNDP PARTNERSHIP| WATER SHED PROTECTION INITIATIVE, VARIRATA NAT. PARK - 11 - 7.0 STAKEHOLDERS & BENEFICIARIES Stakeholders to this project are: 7.1 Conservation and Environment Protection Authority (CEPA), 7.2 Local and International Visitors to the Varirata National Park, 7.3 Local population of Varirata, Sogeri, and Koiari (The Local Land-Owners) people within the Transitional and Discharge Zones of this Water Shed, and 7.4 The Port Moresby City Residents. 8.0 PROJECT SUSTAINABLITY Renewable Fresh water retained within the underground reservoir is safe from evaporation, pollution, contamination from industrial activities and from any uses other than for human and livestock consumption and for soil moisture and vegetation growth.