Rainwater harvesting that is good and right by the needs of household clean water is one of the problems for the people in the islands in Indonesia, especially Merbau Island which is located in the Kepulauan Meranti Regency, Riau Province. The only source of clean water that can be enjoyed easily and cheaply is rainwater. Rainfall on Merbau Island ranges between 2.000 – 4.000 mm per year which is classified as moderate. A survey of 100 randomly selected people was conducted, with a questionnaire containing components for rainwater harvesting (RWH) and other core questions. If available rainfall is used optimally, the need for clean water on the island can be met. Calculation of rainwater for cooking, drinking and washing needs is estimated to be around 15 lpcd. The data obtained is rainfall in 2016 with a total rainfall of 1,754 mm, roof storage area of 36 m2, and the type of roof used is zinc. Rain cycle V2 simulation produces a 3 m3 volume rainwater storage tank, with a construction cost of Rp. 10,365,000. This tank can meet the needs of clean water for five family members for a year.

Daerah aliran sungai Siak bagian hilir merupakan kawasann gambut yang luas dengan kategori gambut sangat dalam (lebih dari 4 meter). Hingga Agutus 2017, berdasarkan laporan Jaringan Kerja Penyelamat Hutan Riau (Jikalahari) jumlah hotspot pada lahan gambut di Provinsi Riau dengan kedalaman lebih dari 4 meter mencapai 397 titik. Kebakaran hutan dan lahan gambut merupakan agenda tahunan Riau, khususnya pada musim kemarau (kering). Tingkat kekeringan suatu daerah dapat diketahui dengan menghitung indeks kekeringannya. Indeks kekeringan merupakan suatu perangkat utama guna mendeteksi, memantau dan mengevaluasi kejadian kekeringan. Salah satu metode guna menghitung indeks kekeringan adalah metode Thornthwaite Mather. Metode tersebut menekankan pentingnya faktor curah hujan dan evapotranspirasi potensial. Analisis kekeringan dilakukan berdasarkan data hujan yang terukur dan tercatat pada 4 stasiun di dalam daerah aliran sungai Siak meliputi Buatan, Kandis, Petapahan Baru dan Pekanbaru. Hasil analisis menunjukan nilai total maksimum indeks kekeringan terjadi pada tahun 2014 dan Tahun 2015 dengan persentase sebagai berikut stasiun hujan Buatan 466,31%, Kandis 398,33%, Petapahan Baru 757,17% dan Pekanbaru 520,77%.

The length of Riau coastlines, Indonesia were approximately 900 km long. Hence, there has been difficulty in prioritizing managing various locations of the coastline damages based on a systematic approach. The objectives of this paper are to apply the state of art in the identification of 16 major coastlines vulnerability index in Riau, and to prioritizing which coastlines should be managed in terms of 4 main aspects such as; technical aspect, economic, environmental, and strategic one. The methodology applied in this paper utilized the combination of the Coastal Vulnerability Index (CVI) and social economic approaches using a Likert’s scale of 1 (low) to 5 (very high). This study has recommended a priority in managing the coastlines in Riau was as follow; Pambang Pesisir, Bengkalis and Tanah Merah, Meranti Islands. These coastlines were calculated as the very high level of vulnerability indexes of 75.3 and 74.9 respectively. This study also simulated the use of shoreline protection structure by Genesis software utilizing a revetment construction. The results showed that the construction of revetment structure in Pambang pesisir beach may reduce the shore erosion rate from 10 m/14 year to 0 m /14 year.

Changes in land use, namely from cultivated land to closed land or settlements, make the water demand in the area increase, if the water that comes out is not balanced with the water that enters the ground, it will cause a decrease in the ground water level. Another problem that arises due to changes in land use is runoff, where runoff occurs due to rainfall exceeding the suction power or infiltration of the soil, so that over time the runoff becomes a puddle and can even cause flooding. One way to overcome these problems is to apply infiltration wells. This case study takes place in the Hang Tuah Cipta Residence Housing Area, Pekanbaru. From the results of field research and Hydrological data analysis revealed that the main existing drainage channel discharge with a discharge capacity of 0.923 m³/s is unable to accommodate the discharge that occurs at 1.19 m³/s. Segment or secondary drainage channels Q12 and Q13 are also unable to accommodate the discharge that occurs at 0.085 m³/s with a capacity of 0.06 m³/s. Based on the analysis results it is planned that the infiltration well with a radius of 0.5 m and a depth of 9 m which has a capacity of 0.0022 m³/s. After the planned discharge infiltration well comes out to be 0.88 m³/s, it means that the discharge does not exceed drainage capacity of 0.923m³/s.

The development of slums in urban areas is inseparable of the increases in population and population activity. In addition, undirected and unplanned development also supports the degradation of the quality of residential environment. One area that is included in the slum area is located in Tanah Datar Sub-District. The residential area of Tanah Datar Sub-District is right in the heart of Pekanbaru city. Thus, living conditions and the welfare of the people who live in these settlements greatly affect the face of a city. The characteristics and conditions of slums in each region is different. Thus, this study aims to identify the condition of a residential area in order to determine alternatives to handling slum areas appropriately. The method used  is exploratory descriptive of phenomena and facts relating to the condition of the community and the environment of slum areas based on real facts, expert opinion and the criteria of the Minister of PUPR Regulation Number 14/PRT/M/2018. The results showed that in achieving the goal of handling slum areas, the priority of government policy and budget allocation alignments be the most important factor. Then, strengthen government collaboration with relevant stakeholders and  handling based on the priority scale required by the residential area.