At first, it was an oddity, the high tides reaching ever higher. The coastal towns were the first to go. We became scared when Venice went under: the pictures in the newspapers showed St Mark’s Square standing nearly a meter deep in water. When Amsterdam drowned, the governments moved to protect New York and London. For a while, sandbags kept back the water, armies of volunteers building the barriers ever higher.
But eventually, the weight of the water was too much. When a breach came, there was no way back.
The world was gone, and in its place was water. Thousands, millions, billions of gallons of water. It lapped gently against the upper floors of the few buildings tall enough to have remained visible. Buildings which now jutted from the surface of a new and terrible ocean like a smattering of curious islands.
The water drowned the cities. For a while, it was only a foot deep. People moved to the upper floors, swapped cars for boats, and continued their business. But the floods kept rising. An early casualty
was drinking water: clean water mixed with sewage and seawater, making the cities uninhabitable. Populations rushed to higher ground. In the United States, everyone moved west: Denver, with its
reputation as the Mile High City, was besieged. In Britain, Harrogate became the new capital. Today, if you take a boat, and look down through the water, you can see the drowned buildings we used to inhabit.
What does the flooded world look like?
• Tropical, with jungles surrounding lagoons.
• Cold, with the tops of buildings poking through vast expanses of
water.
• Wrecked, with debris and wreckage floating past.
The seas probably rose as the monsters arose. If humans or Nature caused the floods, the most likely explanation is a rise in temperature. As the Earth heats, the grounded Antarctic ice melts, and the
waters rise. The water also expands, like other materials, as the temperature rises. As the sea expands, the sea level rises.
Rivers had locks, dams and controls to prevent them from flooding cities and towns along their banks. When they did overflow, there was usually advanced warning that it could happen, organized evacuation and help for those who got trapped or caught in the rising water. None of that exists anymore. There is no early warning system for storms and floods, nor civil or government rescuers. Worse, with nobody to man and operate these facilities, many of them only needed one good rainstorm to overload and cause massive flooding. In areas where levees had changed the flow of the river, towns and cities sprang up in the basin. However, without anyone to maintain the levees and dams, flooding will ravage such locations, permanently engulfing such communities, covering portions of roads and highways, and changing the course of rivers to the way they once were, or creating new paths for the streaming waters. This is not limited to rural areas or downriver communities, urban environments and big cities are equally vulnerable to flooding – think Hurricane Katrina and what it did to New Orleans and other cities and towns. Now imagine there are no emergency relief centers, rescue operations or rebuilding possible. Those communities are permanently swamped and underwater. Gone.
Other urban areas are likely to see temporary flooding that does eventually subside in 2D4 days, but bridges may be washed away, mud, fallen trees and tree branches, vehicles, dead bodies and debris may cover sections of roads, making them difficult or impossible to travel over by vehicle. And things only get worse over time with subsequent floods. Other places may see sewers overflow and spill into transit
tunnels, cellars, basements, and out onto the streets. Naturally, vehicles are taken by moving water, but even standing water can cause most vehicles to stall. Six inches (15 cm) of flood height is all that is needed to stall most commercial vehicles. A foot (0.3 m) or more floats most vehicles, especially in a strong current. If the water reaches the engine, it keeps the pistons from firing and then the vehicle is useless. In some cities the underground subways and tunnel systems, which are far below the natural waterline, may become permanently flooded and/or filled with mud and debris, eventually rendering them completely impassable.
Of course, snakes, rodents and predatory animals lurk down there in the murky depths. Some predators trapped in the mud or debris piles, clawing and biting at anyone who comes within their reach.
Flooding ruins structures and vehicles, but it also buries useful supplies and washes them away. Over time, the rushing water also erodes the land, which can cause buildings to collapse and then fall into the water, sweeping them away. If a survivor group was making runs into a town for supplies, but a massive rainfall
breaks the levee and submerges the town, most dry goods and other supplies are ruined and rendered useless. Whatever remains becomes that much harder to get to, requiring boats and strong swimmers, and finding it under the silt and debris.
Damage via Drowning: People who possess the Swim skill suffer a penalty of -20% and could drown. People who cannot swim need a boat or a piece of floating debris to hang onto or they slide into the water and drown within 1D6 minutes.
Unless a flood victim has a large enough piece of floating debris to lay on without having to exert a lot of energy to hold on, the act of clinging onto something to stay afloat is exhausting. After 1D6+12 hours, the victim suffers damage direct to Hit Points. Reduce Hit Points by one per each additional hour of exposure and exertion (this may be in addition to damage from other injuries. When reduced to one Hit Point, the person cannot hold on any longer, lets go and slips into the watery depths. He can still be saved, but immediate action is necessary; drowns in 1D6 minutes and cannot be resuscitated. Note: This loss of Hit Points also occurs after four days without drinking water and after 1D4 days without food.
If the flood waters are particularly fast-moving, use the damage listed for Coastal Surge/Tidal Wave/Tsunami.
Structural Damage: Long periods of being submerged underwater causes structural damage. Without pumping stations to help get rid of the water and barriers like levees and flood walls to keep more from coming in, flooded areas may stay that way for many weeks, months or years. This eventually degrades the
quality (S.D.C.) of most structures by 50-75%. Some collapsing outright. Those that stay standing get warped and rot and weaken, eventually buckling or crumbling away. This makes those structures that much more dangerous to venture into, even if the upper half is dry and seems relatively safe.
Flooding destroys paper products, books, electronics, and food not sealed in a waterproof container, and soaked clothing, furniture and fabrics are stained and probably ruined. They also become a breeding ground for bacteria, mold, mildew, insects and animals. Flood waters frequently mix with sewage, making it unsafe to drink the water or swim in it, and a source for bacteria, mold and disease even should the waters subside and things dry out.
Flooding is most likely to occur when it rains continuously for several days or comes down rapidly (1D4 inches an hour for 2D4 hours). As always, additional problems and related disaster, like Flooding, is left to the sole discretion of the G.M.
This Disaster May Be Accompanied By: Structure Collapse, Toxic Leakage (from overflowing sewers or broken pipelines) or Landslide/Mudslide