encino | During Sukkot, families of Kesher Israel, a modern Orthodox congregation in Washington, will gather for a special celebration. In the synagogue’s sukkah, they will be treated to a tantalizing array of chocolate cakes and candies, accompanied by delicious cups of — tap water.

“Which are you enjoying more, the sweets or the water?” congregant Evonne Marzouk will ask, knowing that the cups of water will remain largely untouched.

This activity is a reference to Simchat Beit Hashoeva, the festive water ceremony that took place on Sukkot while the Temple was standing. It is part of True Joy Through Water, a new program created by the Orthodox environmental group Canfei Nesharim designed to educate the community about water conservation.

“At the time of the Temple, people lived on the land and understood that if there wasn’t rain, there wasn’t food. That absolute dependence is still true today, but we don’t think about it because we live so far from the land,” said Marzouk, executive director of the three-year-old group.

True Joy Through Water will be celebrated at more than 30 Orthodox congregations in the United States. It is one of many programs that Jewish environmentalists are promoting this Sukkot, which begins on Friday, Oct. 6.

Rabbi Everett Gendler sees another link to the environment through the holiday. “The fragility of the sukkah and its shelter is eloquent testimony to both our dependence on the environment and the environment’s dependence on us,” said Gendler, rabbi emeritus of Temple Emanuel in Lowell, Mass.

Gendler, who admits to a fondness for pumpkins stemming from a pumpkin patch he visited yearly as a youth in the Midwest, invented the Yaakov Lantern. It’s a pumpkin, on which he carves a jack-o’-lantern face on one side and a Star of David on the other. Inside, he places a candle.

At night, the lantern invokes the ushpizin, the biblical ancestors, and lights the sukkah in an environmentally friendly manner.

“It’s hard to imagine the sukkah with wires attached,” said Gendler, who also invented the first solar-powered ner tamid, the light that is always on in a synagogue, and espouses alternative energy sources.

Another longtime environmentalist, Rabbi Arthur Waskow, founder and director of the Shalom Center in Philadelphia, is hosting an expected crowd of some 300 Jews, Christians and Muslims to discuss how religious tradition can help global scorching.

Leaders from the three faiths will speak to the participants, who will build a sukkah together. There will also be petitions on global warming and alternative energy sources which will be delivered to national, state and local legislators.

“I’m hoping to have some direct impact right there on the spot, both in terms of public policy and in terms of congregations’ and congregants’ energy use,” Waskow said.

The event takes place Oct. 8 and celebrates Sukkot, Ramadan and the Feast Day of St. Francis of Assisi. It is part of a nationwide effort initiated by the Tent of Abraham, Hagar & Sarah, a network of Jews, Christians and Muslims.

For Barbara Lerman-Golomb, executive director of Coalition on the Environment and Jewish Life, Sukkot, as a harvest holiday, is a perfect time to talk about organic foods.

“Many individuals who have joined community-supported farms and co-ops are bringing their organically grown fruits and vegetables into the sukkah,” she said.

On the first day of Sukkot, Lerman-Golomb is slated to speak on the Jewish response to environmental issues at the Conservative Kane Street Synagogue in Brooklyn. She will stress the problem of global warming, part of a five-month nationwide campaign that began in August, called How Many Jews Does it Take to Change a Light Bulb?

Richard Schwartz, president of Jewish Vegetarians of North America, views Sukkot as a time to reflect on how future harvests are endangered by global warming, water shortages and soil erosion and depletion.

“As our Israelite ancestors were sustained with manna, a vegetarian food,” while in the desert, he said, “we should sustain ourselves with tofu, the modern-day manna, and other plant foods, for the sake of our health and that of our precious, but imperiled, planet.’