According to britishdam.org, en.wikipedia.org, and www.emerald.com, constructing hotels within the protected catchment (upstream reservation) of a reservoir can undermine water security, ecosystem health, and dam operations. Below is a structured overview of the primary adverse effects and common mitigation measures.

1. Water Quality Degradation

• Discharge of untreated or poorly treated laundry, kitchen, and sanitary wastewater introduces organic matter, nutrients (nitrogen, phosphorus), detergents, and pathogens into inflows. As organic material decomposes, it consumes dissolved oxygen, stressing aquatic life and promoting foul odors and harmful algal blooms.
• Runoff from landscaped areas can carry pesticides, fertilizers, and cleaning-chemical residues into the reservoir, further degrading drinking-water quality and complicating treatment.

2. Enhanced Sedimentation and Erosion

• Clearing of riparian vegetation and soil disturbance during construction dramatically accelerates erosion. The resulting sediment load settles in the reservoir, reducing active storage capacity and clogging intake screens. Over time, this “siltation” forces either costly dredging operations or upstream sediment-management programs to preserve dam functionality.

3. Altered Hydrology and Flood Risk

• Extensive impervious surfaces (roofs, parking lots, access roads) speed rainfall runoff into streams, shortening lag times and heightening peak flows.
• Sudden influxes of stormwater can exceed spillway design capacity, increasing overtopping risk and downstream flood hazards during heavy rainfall events.

4. Biodiversity and Habitat Loss

• Removal of native forest and riparian buffer zones to make way for buildings and recreational amenities fragments wildlife corridors, displaces species, and reduces the natural filtration services that trees and wetlands provide.
• Artificial lighting and noise from hotel operations further disturb nocturnal and breeding behaviors of fish, amphibians, and birds along headwater streams.

5. Increased Water Demand and Resource Competition

• Hotel operations often consume tens to hundreds of thousands of liters of water daily for guest rooms, kitchens, laundry, swimming pools, and irrigation. This additional withdrawal upstream of a reservoir diminishes inflows, especially during seasonal low-flow periods, and can strain allocations for downstream users and ecosystems.

6. Solid Waste and Chemical Contamination

• Inadequate solid-waste handling allows plastics, packaging, and food scraps to enter watercourses, contributing microplastics and promoting vector-attractant conditions.
• Backup generators, vehicle fleets, and maintenance activities pose the risk of diesel, oil, and solvent spills, which can leach into soils and migrate downstream into the reservoir.

7. Visual and Noise Pollution

• Large hotel footprints and associated infrastructure alter the natural landscape, diminishing the aesthetic and recreational value of reservoir headwaters.
• Outdoor lighting and amplified noise from pools, restaurants, or events disrupt the ‘dark-sky’ and quiet-water character prized in protected catchments.

Mitigation and Best Practices

To safeguard the reservoir’s function and ecology, catchment-sensitive design and operations are essential:

• Establish protected buffer zones (minimum 50–100 m) of native vegetation along all watercourses.
• Install advanced wastewater treatment systems (such as membrane bioreactors and constructed wetlands) and enforce zero-discharge policies.
• Use permeable paving, rain gardens, and green roofs to maximize on-site infiltration and slow runoff.
• Implement sediment control measures (silt fences, check dams) during construction, and maintain them until landscapes are re-vegetated.
• Adopt water-savings technologies (low-flow fixtures, greywater reuse, high-efficiency laundry) to reduce withdrawals.
• Enforce a spill-response plan with secondary containment for all fuel and chemical storage.
• Conduct regular environmental monitoring—water quality testing, biological surveys, and sediment surveys—to detect impacts early and adapt management.

By integrating these practices into planning, design, and daily operations, hotels can coexist with upstream reservoir protection goals, preserving both water security and ecological integrity.