אורח חיים תקמ״דOrach Chayim 544

Se’if 1א׳

צָרְכֵי רַבִּים מֻתָּר לַעֲשׂוֹתָהּ בְּחֹל הַמּוֹעֵד, כְּגוֹן לְתַקֵּן הַדְּרָכִים וּלְהָסִיר מֵהֶם הַמִּכְשׁוֹלוֹת; וּלְצַיֵּן הַקְּבָרוֹת כְּדֵי שֶׁיִּזָּהֲרוּ מֵהֶם הַכֹּהֲנִים; וּלְתַקֵּן הַמִּקְוָאוֹת. הַגָּה: וְדַוְקָא צָרְכֵי רַבִּים כָּאֵלּוּ, שֶׁהֵם צְרִיכִים לְגוּף הָאָדָם, אֲבָל שְׁאָר צָרְכֵי רַבִּים כְּגוֹן בִּנְיַן בה"כ (בֵּית יוֹסֵף בְּשֵׁם תְּשׁוּבַת הָרַשְׁבָּ"א), אָסוּר לַעֲשׂוֹת בַּמּוֹעֵד; וְהוּא הַדִּין דְּלִשְׁאָר צָרְכֵי מִצְוָה אָסוּר לַעֲשׂוֹת מְלֶאכֶת אֻמָּן בַּמּוֹעֵד (ריב"ש סִימָן רכ"ו).

1. The Laws of Public Needs During Chol HaMoed, 2 Seifim: It is permitted on Chol HaMoed to take care of the needs of the community, such as fixing roads and removing stumbling blocks (or obstacles) from them, and to mark (or point out) graves so the priests can be warned about them, and to fix the Mikvahs. RAMA: Specifically public needs like needs for the person's body (or well being) but other public needs, like building a synagogue (Beis Yosef in the name of the Teshuvos HaRashbah) are forbidden to do during Chol HaMoed. And this is the law for other mitzvah related needs - it is forbidden to perform artistic work during Chold HaMoed (Rivash, Siman 226).

Se’if 2ב׳

בּוֹרוֹת וּמַעְיָנוֹת שֶׁל רַבִּים שֶׁנָּפַל בָּהֶם עָפָר וַאֲבָנִים וְנִתְקַלְקְלוּ, מֻתָּר לְתַקְּנָם וַאֲפִלּוּ אֵין רַבִּים צְרִיכִים לָהֶם עַתָּה, כֵּיוָן שֶׁאֵינוֹ מַעֲשֵׂה אֻמָּן; אֲבָל לַחְפֹּר לָהֶם בּוֹרוֹת מֵחָדָשׁ, שֶׁהוּא מַעֲשֵׂה אֻמָּן, אִם הָרַבִּים צְרִיכִים לָהֶם עַתָּה מֻתָּר אֲפִלּוּ אִם כִּוְּנוּ מְלָאכְתָן בַּמּוֹעֵד, וַאֲפִלּוּ בְּפַרְהֶסְיָא וּבְטִרְחָא יְתֵרְתָּא; וְאִם אֵין צְרִיכִים לָהֶם עַתָּה, לֹא יַעֲשׂוּ. אֲבָל בּוֹרוֹת שִׁיחִין וּמְעָרוֹת שֶׁל יָחִיד אָסוּר לַחְפֹּר אוֹתָם מֵחָדָשׁ, וַאֲפִלּוּ צָרִיךְ לָהֶם עַתָּה; וְאִם הָיוּ עֲשׂוּיִם כְּבָר, וְנִתְקַלְקְלוּ, אִם צָרִיךְ לָהֶם עַתָּה מֻתָּר לְתַקְּנָם; וְאִם אֵין צָרִיךְ לָהֶם עַתָּה אָסוּר לְתַקְּנָם, אֲבָל מֻתָּר לְהַמְשִׁיךְ מַיִם לְתוֹכָן אֲפִלּוּ אֵין צָרִיךְ לָהֶם עַתָּה.

2. It is permitted to fix wells or springs that have broken down due to dirt and stones falling into them, even if it is not a public need at the moment; such as if it is artistic or aesthetic work. But it is permitted to dig new wells that are expert/artistic/aesthetic if the public needs them immediately. Even if they intentionally did/planned the work during Chol HaMoed; and even for publicity and additional effort . And if they do not need it immediately, they should not do it. However, personal wells, pits and springs cannot be dug anew, even if he needs them immediately. If he made them already and they became broken, if he needs them immediately it is permissible to fix them. If he does not need them immediately it is forbidden to fix them. However, it is permitted to put water in them even if he does not need it immediately.